which of the following statements is not always true?

a + (-b ) = -b + a

(a + b) + (-c) = a + [b + (-c)]

-(-a) = a

a - (-b) = (-b) -a

Answer:

b is correct

Step-by-step explanation:

Answer:

3a(c + 2b - 5)

Step-by-step explanation:

Step-by-step explanation: The greatest common factor for the 3 terms here is 3a so factor out a 3a and what we're left with inside the parentheses is each of the terms in the original polynomial divided by 3a.

So we have 3a(c + 2b - 5) which is our final answer.

Answer:

147.92

Step-by-step explanation:

Let the monthly salary be x

He saves 12 % and that is 17.75

x* 12% = 17.75

Change to decimal form

x *.12 = 17.17

Divide each side by .12

x*.12 /.12 = 17.75/.12

x =147.91666666

Rounding to the nearest cent

x = 147.92

Answer:

x=34[tex]\sqrt{2}[/tex]

y=34[tex]\sqrt{3}[/tex]

Step-by-step explanation:

Answer:

a. y= f(x-1)

Step-by-step explanation:

___________

Answer:

0.2754

Step-by-step explanation:

Probability of saving a penalty kick = 0.617

p = 0.617 ; q = 1 - p = 1 - 0.617 = 0.383

number of trials, n = 7

Number of saves, x = 5

Using the binomial probability relation :

P(x = x) = nCx * p^x * q^(n-x)

P(x = 5) = 7C5 * 0.617^5 * 0.383^2

P(x = 5) = 21 * 0.0894181 * 0.146689

P(x = 5) = 0.2754

Answer:

36

Step-by-step explanation:

5(4)+16=20+16=36

Answer:

I'm pretty sure it is D since all the other ones are maximum value parabolas (and the questions asks for a minimum) other than D.

e

measure of center

as A measure that describes the typical value of a data set mean,median and mode.

Answer: -2x^6+x^5-x^3-2+2x^2 Hope that helps!

Step-by-step explanation:  

1. Remove Parentheses x^6-2x^5-x^3-7-3x^6+3x^5+2x^2+5

2. Collect like terms (x^6-3x^6)+(-2x^5+3x^5)-x^3+(-7+5)+2x^2

3. Simplify and your answer would be -2x^6+x^5-x^3-2+2x^2

Answer:

26 papers

Step-by-step explanation:

Well this is pretty straight forward

if he can grade 6 papers an hour

we just multiply 6 by 7 to get how many papers he graded in 7 hours

6*7= 42

now we subtract 42 from 68 to get how many papers are left to be graded

68-42=26

26 papers are left

Answer:

98 π R

Step-by-step explanation:

Surface area of sphere = 4 π R²

= 2 π R × 2 R

= 49 π × 2 R

= 98 π R

Answer:

1000 combinations

Step-by-step explanation:

Answer:

201.1 mm²

Step-by-step explanation:

Smaller sphere = 8

Larger sphere = 15

Larger sphere surface area = 706.9 mm²

Smaller sphere surface area = x

Hence:

Since we are dealing with surface area

8²/15² = x/ 706.9

Cross Multiply

15² × x = 706.9 × 8²

x = 706.9 × 8²/15²

x = 201.07377778 mm²

x ≈ 201.1 mm²

Therefore, the surface area of the smaller sphere is 201.1 mm²

Answer:

[tex]\frac{1}{12}[/tex] or 1:12

Step-by-step explanation:

There are 11 teachers : 132 students

Because ratios are just another way of writing fractions, by putting this into a fraction we get:

[tex]\frac{11}{132}[/tex]

Dividing both the numerator and denominator (top and bottom) by 11, we get:

[tex]\frac{1}{12}[/tex]

Thus, the ratio is [tex]\frac{1}{12}[/tex], or 1:12

Answer:

65 cm

Step-by-step explanation:

16^2 x 63^2 = 65^2

Answer:

-1/2

Step-by-step explanation:

y2-y1/x2-x1 is the formula

-2-(-1)/-6-(-8) = -1/2

Hope this helps.

Answer:

A = 6 x 7

Step-by-step explanation:

To find the area of a parallelogram we use the equation of Area = base x height. In this case since the base is 6 and the height is 7, we plus in these numbers for the variables (b x h) to get the area.

9514 1404 393

Answer:

  4

Step-by-step explanation:

Consider the arcs PQ and P'Q. When turns are made without slipping, these have the same measure. The length of arc PQ is ...

  PQ = CP·θ

The length of arc P'Q is ...

  P'Q = O₂Q·(∠PO₂Q)

Segment O₂A is parallel to CP, so angle AO₂Q is θ. Then ∠PO₂Q = θ+α, where α is the angle by which P' has rotated counterclockwise from A.

We are given that ...

  CP = 5, O₂Q = 1

Using the above relations, we can write ...

  5θ = 1(θ+α)

  α = 4θ

That is, for every full turn θ = 2π, the smaller circle makes turns totalling 4(2π) = 8π, or 4 full turns.

The small circle makes 4 revolutions to arrive at its starting point.

Answer:

52

Step-by-step explanation:

If JK bisects the angle, the two angles are equal

6x+2 = 8x-6

Subtract 6x from each side

6x-6x+2 = 8x-6x-6

2 = 2x-6

Add 6 to each side

2+6 =2x-6+6

8 =2x

Divide by 2

8/2 =2x/2

4 =x

Now find angle LJM, which is the sum of the two angles

6x+2 + 8x-6

14x -4

14*4-4

56-4

52

Answer:

D) 52

Step-by-step explanation:

since htere is an angle bisector that means that (6x+2) and (8x-6) are equal to each other

so

(6x+2)=(8x-6)

-6x         -6x

2=2x-6

+6    +6

8=2x

/2 /2

x=4

no you plug x back into one of the equations so

6(4)+2=26

now 26x2=52

Answer:

i think its 54. i might be incorrect.

Step-by-step explanation:

Answer:

54º

Step-by-step explanation:

This really cannot be determined because the combined angle is not marked as 90º

let's assume it is 90º

(7x + 12) +(2x + 24) = 90

Combine like terms

9x + 36 = 90

Subtract 36 from both sides

9x = 54

Divide both sides by 9

x = 6

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

7(6) + 12 = 54º

2(6) + 24 = 36º

54º is the larger angle

Answer:

8.6cm

Step-by-step explanation:

V = 4/3 pi r^3 = 334, solve for r = 4.30

double for diameter = 8.61

Step-by-step explanation:

you can see there

just click the photo

Slope:  

2

3

y-intercept: (0,−6)xy0−63−4

Answer:

h= x/ x+4

Step-by-step explanation:

Move all terms to the left side and set equal to zero, Then set each factor equal to zero.

Answer:

10x+ y

Step-by-step explanation:

The unit's digit is y and the ten's digit is x.

The ten's digit has a zero placed beside it .

So multiply x by 10  giving 10 x and then add the unit's digit .

This wil give 10x+ y

The number is 10 x + y

This can be elaborated through the use of numbers . Suppose we have unit's digit as 6 and the ten's digit as 5.

Multiply 10 by 5 and add 6

5*10 +6= 50+6= 56

Answer:

The value for x is -2 and the value for y is -10 .

Step-by-step explanation:

Firstly , let's write the equations

solving equation 1 to get the values of x

          or ,    -2x+3=7          

      or,  -2x+3-3 =7-3 (subtracting -3 on both sides )

       or ,  -2x=4

        or,  -2x/2  =   4/2  (dividing  by two on both sides )

         or ,  -x =2

           or  x = -2

now let's substitute the values of x  in the equation 2

           3x+1 =5+y (writing second equation as it is )

           or, 3x+1-1=5+y-1 (subtracting  -1 on both sides )

            or , 3x = 4+y  

              or , 3 × -2 = 4+y  (substituting the values of x from equation 1 )

                or ,  -6  =  4 +y

                   or ,  -6-4 = 4+y-4 ( subtracting -4 on both sides  )

                     or ,    -10 = y

      Therefore the values of x and y is -2 and  -10 respectively .

                Hope it helped you .  If you find the answer useful  please rate brainliest , If not Thanks anyway .

For the case of a line through

(

2

,

7

)

and

(

1

,

−

4

)

we have

slope

m

=

Δ

y

Δ

x

=

−

4

−

7

1

−

2

=

−

11

−

1

=

11

Using the point

(

2

,

7

)

we can write the equation of the line in point slope form as:

y

−

7

=

m

(

x

−

2

)

where the slope

m

=

11

.

That is:

y

−

7

=

11

(

x

−

2

)

To get point intercept form, first expand the right hand side so...

y

−

7

=

11

x

−

(

11

⋅

2

)

=

11

x

−

22

Then add

7

to both sides to get:

y

=

11

x

−

15

=

11

x

+

(

−

15

)

This is point intercept (

y

=

m

x

+

c

) form with slope

m

=

11

and intercept

c

=

−

15

.

Mean=23

Median=21.5 its a hard one to do so yeah

Modes=28

Range=22

Answer:

153.9

Step-by-step explanation:

14/2=7 which is the radius which you square and it results to 49. multiply that times pi for 153.86 or 153.9 to the nearest tenth.

Answer:

153.9

Step-by-step explanation:

We know that the equation to find the area of a circle in [tex]\pi r^2\\[/tex]. So we divide the diameter by half and we plug in the radius.

Answer:

0.06

Step-by-step explanation: