-4x + 7y = 18
4x - y = -3
solve using either the substitution or elimination method
pls show solving steps
will mark brainliest​

Answer:

The original price was 400 dollars.

Step-by-step explanation:

400 times 0.4 equals 160. 400 minus 160 equals 240. Therefore the answer is 400 dollars.

Answer: The above Table 1 will calculate the population size (N) after a certain length of time (t). All you need to do is plug in the initial population number (No), the growth rate (r) and the length of time (t). The constant (e) is already entered into the equation. It stands for the base of the natural logarithms (approximately 2.71828). Growth rate (r) and time (t) must be expressed in the same unit of time, such as years, days, hours or minutes. For humans, population growth rate is based on one year. If a population of people grew from 1000 to 1040 in one year, then the percent increase or annual growth rate is 40/1000 x 100 = 4 percent. Another way to show this natural growth rate is to subtract the death rate from the birth rate during one year and convert this into a percentage. If the birth rate during one year is 52 per 1000 and the death rate is 12 per 1000, then the annual growth of this population is 52 - 12 = 40 per 1000. The natural growth rate for this population is 40/1000 x 100 = 4%. It is called natural growth rate because it is based on birth rate and death rate only, not on immigration or emigration. The growth rate for bacterial colonies is expressed in minutes, because bacteria can divide asexually and double their total number every 20 minutes. In the case of wolffia (the world's smallest flowering plant and Mr. Wolffia's favorite organism), population growth is expressed in days or hours.

Each wolffia plant is shaped like a microscopic green football with a flat top. An average individual plant of the Asian species W. globosa, or the equally minute Australian species W. angusta, is small enough to pass through the eye of an ordinary sewing needle, and 5,000 plants could easily fit into thimble.

See Straight Pin & Sewing Needle Used In Wayne's Word Articles

There are more than 230,000 species of described flowering plants in the world, and they range in size from diminutive alpine daisies only a few inches tall to massive eucalyptus trees in Australia over 300 feet (100 m) tall. But the undisputed world's smallest flowering plants belong to the genus Wolffia, minute rootless plants that float at the surface of quiet streams and ponds. Two of the smallest species are the Asian W. globosa and the Australian W. angusta. An average individual plant is 0.6 mm long (1/42 of an inch) and 0.3 mm wide (1/85th of an inch). It weighs about 150 micrograms (1/190,000 of an ounce), or the approximate weight of 2-3 grains of table salt. One plant is 165,000 times shorter than the tallest Australian eucalyptus (Eucalyptus regnans) and seven trillion times lighter than the most massive giant sequoia (Sequoiadendron giganteum).

See Photo Of Massive Giant Sequoia Tree

See Photo Of The Australian Wolffia angusta

See Photo Of The Indian Wolffia microscopica

See Additional Color Images Of Wolffia Species

The growth rate for Wolffia microscopica may be calculated from its doubling time of 30 hours = 1.25 days. In the above population growth equation (N = Noe rt), when rt = .695 the original starting population (No) will double. Therefore a simple equation (rt = .695) can be used to solve for r and t. The growth rate (r) can be determined by simply dividing .695 by t (r = .695 /t). Since the doubling time (t) for Wolffia microscopica is 1.25 days, the growth rate (r) is .695/1.25 x 100 = 56 percent. Try plugging in the following numbers into the above table: No = 1, r = 56 and t = 16. Note: When using a calculator, the value for r should always be expressed as a decimal rather than a percent. The total number of wolffia plants after 16 days is 7,785. This exponential growth is shown in the following graph where population size (Y-axis) is compared with time in days (X-axis). Exponential growth produces a characteristic J-shaped curve because the population keeps on doubling until it gradually curves upward into a very steep incline. If the graph were plotted logarithmically rather than exponentially, it would assume a straight line extending upward from left to right.

Sixteen days of exponential growth in Wolffia microscopica.

Wolffia plants have the fastest population growth rate of any member of the kingdom Plantae. Under optimal conditions, a single plant of the Indian species Wolffia microscopica may reproduce vegetatively by budding every 30 hours. One minute plant could mathematically give rise to one nonillion plants or 1 x 1030 (one followed by 30 zeros) in about four months, with a spherical volume roughly equivalent to the size of the planet earth! Note: This is purely a mathematical projection and in reality could never happen!

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

i to an odd power is 1 and i to an even power is -1 so you can see it is A

Answer:

C- C=0

Step-by-step explanation:

Answer: 3

Step-by-step explanation:

Answer:

n = 3

Step-by-step explanation:

dont remember exactly how we did it in class but went through this question

Answer:

112 degrees

Step-by-step explanation:

The other 2 interior angles are (180-44)/2 which is 68.

180 (straight line) -68 = 112

Answer:

8.68

Step-by-step explanation:

just multiply 124.00 times 0.07 and that's it

Step-by-step explanation:

Let A be the tens digit of the number and B be the ones digit.

We have A + B = 10 and 10A + B - 36 = 10B + A.

=> A + B = 10 and 9A - 36 = 9B

=> A + B = 10 and A - 4 = B

=> A + B = 10 and A - B = 4

Therefore 2A = 10 + 4 = 14,

A = 7 and B = 10 - 7 = 3.

Hence the number is 73.

Answer:

Yes, he has exactly the right amount

Step-by-step explanation:

Buster- 20. 5 = 2 days  20.5+20.5+20.5+10.25= 71.75 for 7 days

Roxy- 22.5= 3 days 22.5+22.5+11.25=56.25 for 7 days

71.75+56.25= 128oz

Brian will have exactly enough food for 7 days

Here ∠13 & ∠15 are corresponding angles , so they are equal [ ∠13 = ∠15 ]

As per the question ,

⇒ 2x - 3 = 71°

⇒ 2x = 71 + 3

⇒ 2x = 74

⇒ x = 74 ÷ 2

⇒ x = 37

Hence , x = 37

Answer:

O (8, -6)

Step-by-step explanation:

brainiest plz

Answer:

(-6,8)

Step-by-step explanation:

Have a good day

The answer is 13 by using Pythagorean theorem.

Answer:

2x(x+1)(5x+7)

Step-by-step explanation:

10x^3+24^2+14

2(5x^3+12x+7)

2x(5x^2+12x+7)

2x(x+1)(5x+7)

2x(2x+1)(5x+7)

Answer:

y + 8 = -12(x - 8)

General Formulas and Concepts:

Algebra I

Point-Slope Form: y - y₁ = m(x - x₁)  

Step-by-step explanation:

Step 1: Define

Point (8, -8)

Slope m = -12

Step 2: Write Function

Substitute variables into general form.

y + 8 = -12(x - 8)

Answer:

A = $697.09

Step-by-step explanation:

A = P (1 + r/n)

A = 600 (1 + 0.05/365)

A = $697.09

Answer:

its 2.60 for each pendent

Answer:

y = 3x + 3

Step-by-step explanation:

...............................

Answer:

Step-by-step explanation:

V of a sphere is (4/3)*pi*r³, and because we have 3 scoops

V = 3* (4/3) * 3.14 * 4³ = 4* 3.14 * 4³ = 803.84 cm³

Answer:

b

Step-by-step explanation:

Answer:

-400i

General Formulas and Concepts:

Algebra II

Step-by-step explanation:

Step 1: Define

z = -400i - 44.5

Step 2: Identify

Treat imaginary i as a variable. The imaginary part of z would be the entire term of i. Therefore, our answer is -400i

Answer:

[tex]x=72[/tex]

Step-by-step explanation:

[tex]\frac{x}{2} -12=24[/tex]

[tex]x-24=48[/tex] (multiply [tex]2[/tex] on both sides)

[tex]x=72[/tex]

Hope this helps :)

Answer:

1/6

Step-by-step explanation:

1/2 divided by 3

Answer:

36

Step-by-step explanation:

16*2 = 32

16*1/4 = 4

32+4 = 36

Answer:  She will need 36 yards of material.

Step-by-step explanation:

16 × 2¹/₄ can be done different ways,

First multiply ¹/₄ times 16. that is the same as dividing 16/4 = 4

Then multiply 2 times 16  2×16 = 32

Add 32 + 4 = 36

Another way is to change 2¹/₄ to an improper fraction and multiply

⁹/₄ × 16

   16

  ×9

   54  

+9  

 144

144/4 = 36

Answer:

41/10

Step-by-step explanation:

Answer:

Based on what you asked i think the answer would be 4 1/10

Step-by-step explanation:

Answer:

9/21 & 7/21

Step-by-step explanation:

Equivalent fraction for  [tex]\frac{3}{7}[/tex] and  [tex]\frac{1}{3}[/tex] using 21 using as the common denominator are [tex]\frac{9}{21} ,\frac{7}{21}[/tex].

"Equivalent fraction is fraction with different numerator or denominator

that represents the same value or proportion of the whole."

"Common denominator is the same denominator of all the fraction"

We have to write an equivalent fractions for [tex]\frac{3}{7}[/tex] and [tex]\frac{1}{3}[/tex]  using 21 as common denominator.

As we know when we multiply [tex]7[/tex] by [tex]3[/tex] to get [tex]21[/tex]

and we have to multiply [tex]3[/tex] by [tex]7[/tex] to get [tex]21[/tex]

⇒[tex]\frac{3}{7}=\frac{3}{7}[/tex]×[tex]\frac{3}{3}=\frac{9}{21}[/tex]

⇒[tex]\frac{1}{3}=[/tex][tex]\frac{1}{3}[/tex]×[tex]\frac{7}{7}=\frac{7}{21}[/tex]

Hence, Equivalent fraction for  [tex]\frac{3}{7}[/tex] and  [tex]\frac{1}{3}[/tex] using 21 as common denominator are [tex]\frac{9}{21} ,\frac{7}{21}[/tex].

Learn more about Equivalent fraction and common denominator here

https://brainly.com/question/26277885

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Answer:

17. $2194.80; 18. $1147.20

Step-by-step explanation:

I=prt; I = interest, p = principle, r = rate, t = time

plug in and go

17.

I = 1860(.06)3

I = 1860(.18)

I = 334.8

334.8 + 1860 + $2194.80

18.

I = 960(.065)3

I = 960(.195)

I = 187.2

187.2 + 960 = $1147.20