It takes Brian 15 hours longer to build a model car than it takes John. If they work together, they can build the model car in 4 hours. Using complete sentences, explain each step in figuring out how to determine the time it would take Brian to build the car on his own. (10 points)

Answers

Answer 1

Answer:

1/x + 1/( x+15 ) = 1/4  / · x ( x+15 )

   x+15 + x = x ( x+15 ) /4      / · 4

   8 x + 60 = x² + 15 x

   x² + 15 x - 8 x - 60 = 0

   x² + 7 x - 60 = 0

   x² + 12 x - 5 x - 60 = 0

   x · ( x + 12 ) - 5 ·( x+ 12 ) = 0

   ( x + 12 ) · ( x - 5 ) =0

   x = - 12  ( not accepted ) or  x = 5

   The time taken by Brian:  5 + 15 = 20 hours

Step-by-step explanation:


Related Questions

a.What is the length of A’A?
b.What is the length of B’B
Both in units

Answers

Answer:

A'A = 18 units, B'B = 9 units

Step-by-step explanation:

Δ ACB and Δ A'CB' are similar triangles, thus the ratios of corresponding sides are equal, that is

[tex]\frac{AC}{A'C}[/tex] = [tex]\frac{AB}{A'B'}[/tex] , substitute values

[tex]\frac{AC}{12}[/tex] = [tex]\frac{20}{8}[/tex] ( cross-  multiply )

8AC = 240 ( divide both sides by 8 )

AC = 30

Thus A'A = AC - A'C = 30 - 12 = 18 units

--------------------------------------------------------------------

and

[tex]\frac{CB}{CB'}[/tex] = [tex]\frac{AB}{A'B'}[/tex] , that is

[tex]\frac{CB}{6}[/tex] = [tex]\frac{20}{8}[/tex] ( cross- multiply )

8CB = 120 ( divide both sides by 8 )

CB = 15

Thus

B'B = CB - CB' = 15 - 6 = 9 units

Math I need help 8th grade

Answers

Answer:

Part A x=60

Step-by-step explanation:

68+52= 120

180-120=60

So x=60

WILL GIVE BRAINLST FOR WHOEVER ANSWERS FIRST Which of the following equations is equivalent to 6(3p – 2) = 20?
Group of answer choices


9p – 4 = 20


9p – 8 = 20


18p – 12 = 20


18p – 2 = 20

Answers

It would be the 3rd option, because you multiply 6 and 3 and get 18, and then multiply 6 and 2 and get 12 so it would be 18p-12=20

The Rock Zoo nurses 37 species of big cats. Recently, a few species of big cats were sponsored to other zoos around the country. The zoo now nurses only 25 species. How many species of big cats were sponsored to other zoos?

Write the equation to be used to solve this equation.

Answers

Answer:

12 species

Step-by-step explanation:

37-N=25

working backwards

25-37=N

=25-37=12

Marge's plan costs .14 cents per minute plus a monthly fee of $24. Dan's plan costs .12 cents per minute plus a monthly fee of $28. How many minutes (m) are required for both plans to cost the same for the month?

Answers

Answer:

6 min for Marge's and 7 for Dan's plan

Step-by-step explanation:

0.14x6=0.84

0.12x7=0.84

12=6x+3y solve for y

Answers

Answer:

1 1/3 = y

Step-by-step explanation:

12 = 6x + 3y

12 = 9y

12/9 = y

1 1/3 = y

Hope this helped!

Plsss helppppssssss me :< and explain thatttttt

Answers

Answer:

you need to take a better picture nobody can see that i not trying be be rude

Step-by-step explanation:

Answer:

upload clear picture, it is very easy

Step-by-step explanation:

A school has $15,000 to spend on computer monitors. The school plans to purchase 200 monitors for $89 each. A teacher completes the calculations below and concludes that the school has enough money to buy the monitors. 200 × 89 = (200 × 8) + (200 × 9) = 1,600 + 1,800 = 3,400

Answers

Answer:

Since the budget of the school is $15,000, the school does not have enough money to buy the monitors

Step-by-step explanation:

The school plans to purchase 200 monitors for $89 each.

This is the calculation of the teacher

200 × 89 = (200 × 8) + (200 × 9) = 1,600 + 1,800 = 3,400

The teacher's calculation is wrong

The correct calculation using Distributive property is

a(b + c) = ab + ac

200 × 89 = 200(80) + 200(9)

Because 80 + 9 = 89

Hence,

200 × $89 = 16000 + 1800

= $17,800

Since the budget of the school is $15,000, the school does not have enough money to buy the monitors

$17, 800 ≠ $15,000

Which expressions are equivalent to 3x + 3(x + y)?
Choose all answers that apply:
A 6x + 3y
B 3(x + x + y)
C 3ay

Answers

3x + 3(x + y)

3x + 3x - 3y

6x - 3y

your answer would be A

Answer:

A and B

Step-by-step explanation:

3x+3(x+y)

3x+3x+3y

6x+3y

B

3(x+x+y)

3x+3x+3y

6x+3y

Write the proportional equation that represents the table below.

Answers

The answer is b y=20x

The number of free spng to download is determined by usomg a ratio. When you purchase 40 songs, you get 24 free song download. How many songs must you purchase in order to get 6 free song downloads?​

Answers

Answer:

10

Step-by-step explanation:

set up a proportion, 40/24 and x/6, 6 times 40 = 240, divide by 24 to get 10


Candace is a salesperson at the local boat store. She receives a 14% commission on every sale that she makes. How much commission does Candace
make on a boat that sells for $1,995?

Answers

Answer: 00000

Step-by-step explanation:

12 divided by 18/25 is?!?!

Answers

Answer:

16.6

Step-by-step explanation:

12 divided by 18/25 is 16.66.

Given:

12 divided by 18/25

12÷18/25

12÷0.72

=16.66

What is division?

Division is one of the four basic operations of arithmetic, the ways in which numbers are combined to form new numbers. To divide rational expressions, multiply the first fraction by the reciprocal of the second. If we rewrite  division as the product of the first expression by the inverse of the second, we add them all and look for common factors.

The way  something is shared is called a sharing method. There are  three types of distribution methods according to the degree of difficulty. They are division method or division by repeated subtraction, short division method or bus stop method and long division method.

To learn more about division, refer;

https://brainly.com/question/21416852

#SPJ2

Which of Talia's steps is incorrect? Step 1 is incorrect because it uses a point that is not on the line. Step 2 is incorrect because it uses a point that is not on the line. Step 3 is incorrect because it shows an incorrect ratio for the slope. Step 4 is incorrect because it shows an incorrect substitution of (1, 3) into the point-slope form.

Answers

Answer:

Step 3 is incorrect because it shows an incorrect ratio for the slope.

Step-by-step explanation:

The correct question is:

Talia wants to write the equation of the graphed line in point-slope form. These are the steps she plans to use:

Step 1: Choose a point on the line, such as (2, 5).

Step 2: Choose another point on the line, such as (1, 3).

Step 3: Count units to determine the slope ratio. The line runs 1 unit to the right and rises 2 units up, so the slope is .

Step 4: Substitute those values into the point-slope form.

y – y1 = m(x – x1)

y – 3 = (x – 1)

Which of Talia’s steps is incorrect?

Step 1 is incorrect because it uses a point that is not on the line.

Step 2 is incorrect because it uses a point that is not on the line.

Step 3 is incorrect because it shows an incorrect ratio for the slope.

Step 4 is incorrect because it shows an incorrect substitution of (1, 3) into the point-slope form.

Answer:

Step 1 is correct because from the graph, points (1,3) and (2,5) lies on the line so the points can be used to find the slope.

Step 2 is also correct.

Step 3 is incorrect. Slope of a graph is the ratio of vertical change to horizontal change. The vertical change is the rise while the horizontal change is the run, hence slope is the ratio of rise to run.

Since the line runs 1 unit to the right and rises 2 units up, so the slope is 2/1 = 2

Therefore the correct point-slope form is:

y – y1 = m(x – x1)

y – 3 = 2(x – 1)

Step 4 is correct, because i t shows an incorrect substitution of (1, 3) into the point-slope form.

Answer:

c

Step-by-step explanation:

took the quiz!!

solve for x


-30=5(x+1)

Answers

Answer:

-7

Step-by-step explanation:

LM is a perpendicular bisector of NP The length of LN is 12w +7, and the length of LP is 15w 5. What is the length of LN?

Answers

Answer:

[tex]LN = 55[/tex]

Step-by-step explanation:

Given

[tex]LN = 12w + 7[/tex]

[tex]LP = 15w - 5[/tex]

Required

Determine LN

Since LM is a bisector, then we have:

[tex]LP = LN[/tex] (See attachment for illustration)

[tex]15w - 5 = 12w + 7[/tex]

Collect Like Terms

[tex]15w - 12w = 5 +7[/tex]

[tex]3w = 12[/tex]

Solve for w

[tex]w = 12/3[/tex]

[tex]w = 4[/tex]

LN is calculated as thus:

[tex]LN = 12w + 7[/tex]

Substitute 4 for w

[tex]LN = 12 * 4 + 7[/tex]

[tex]LN = 48 + 7[/tex]

[tex]LN = 55[/tex]

help me!!!!!!! I need help​

Answers

Answer:

the  answer is 8

Step-by-step explanation:

BC

Answer:

8

Step-by-step explanation:

18-inches is 1.5 feet.

-2 ( 1/4x + 2) > or equal to 5

Answers

-2(1/4x+2) >= 5
-0.5x-4 >= 5
-0.5x >= 9
x >= -18

The quotient of (x5 - 3x3 - 3x2 - 10x + 15) and a polynomial is (x2 - 5). What is the polynomial?

Answers

Answer:

x^3 + 2x - 3

Just divide x^5-3x^3-3x^2-10x+15 by the quotient and you get the polynomial searched.

Step-by-step explanation:

hope it helps , i am in 6th grade and i have got this answer from an elder student.

-3 = 1 3/5 + m .
what is m

Answers

Answer:

m = -4 3/5   or   -4.6

Step-by-step explanation:

First, we need to isolate the variable, m. We subtract 1 3/5 on both sides of the equation, and then we should get -4 3/5 = m.

hope this helped !! :D

Check all fractions equivalent to 2⁄8.
Check all that are true.

1⁄2

1⁄6

4⁄16

1⁄4

4⁄12

Answers

1/4 and 4/16 are equivalent to 2/8

i will mark you as brainliest please help!!

Answers

Answer:

y=x

Step-by-step explanation:

y1 is -4 and x1 is -4 so I think that's the amswer

12. The table shows the height in feet of a stack of medium sized moving boxes. What is the height of a stack of 14 boxes

Answers

height = 2.25 * box.

So, 14 boxes = 2.25 * 14 = 31.5.

need these 3 problems answered
1.(2x-3)^2+24=0
2.(3x+1)^2-49=0
3.3x^2-12x=-45

Answers

Answer:

ummm ................

What is 13 / 143 as a unit fraction

Answers

Answer:1/11

Just got it using some brain cells >:)

Answer:

1/11

Step-by-step explanation:

13/143=1/11

-13 (q + 4) = 7 q + 16

Answers

Answer:

q=3.4

Step-by-step explanation:

-13q+-52=7q+16

-52=20q+16

-68=20q

-68/20 is -3.4

The value of x must be greater than
O 0
O 1
O 3
O 7​

Answers

3 Because the length of the two would not have to make it seven so it’s got to be three

Guys pls answer this for me in a minute it is really hard

Answers

The answer to the question is B
The answer is B... hope it helps

Is 123456789098765432172 is divisible by 18?

Answers

Answer:

123456789098765432172 is NOT divisible by 18. When it is divided out you are left with a decimal! :)

Step-by-step explanation:

GIVING BRAINLIEST!!! A student observes a beaker of room temperature water resting on a table. She states that the beaker of water does not have any energy. Which statement below is accurate regarding her observation?
a. She is correct because the beaker of water is not moving.


b. She is incorrect because the beaker of water has thermal energy.


c. She is incorrect because all water contains hydrogen and oxygen.


d. She is correct because the beaker of water is at room temperature.

Answers

Answer:

b

Step-by-step explanation:

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