All categories

3 years ago

Solve the linear system of equations 8x−4y=20 5x−8y=62 x= y=

Mathematics

1 answer:

LUCKY_DIMON [66]3 years ago

3 0

Answer:

x = -2

x = -9

Step-by-step explanation:

The linear system is:

8x - 4y = 20 ⇒ (1)

5x - 8y = 62 ⇒ (2)

To solve the system multiply equation (1) by -2 to make the coefficients of y equal in values and different in signs, then add the resulting equation with equation (2)

∵ -2(8x) + -2(-4y) = -2(20)

∴ -16x + 8y = -40 ⇒ (3)

- Add equation (2) and (3)

∴ -11x = 22

- Divide both sides by -11

∴ x = -2

Substitute the value of x in equation (1) or (2)

∵ 8(-2) - 4y = 20

∴ -16 - 4y = 20

- Add 16 to both sides

∴ - 4y = 36

- Divide both sides by -4

∴ y = -9

You might be interested in

Are rectangles abcd and wxyz congruent? why or why not? yes, all right angles were preserved. yes, both rectangles have an area

Alexxx [7]

The correct answer is D.

3 0

3 years ago

Read 2 more answers

A population of fish in a lake is 14000 in 2010. The population decreases 6% annually. What is the population in 2019

kodGreya [7K]

Answer:

8022.

Step-by-step explanation:

Let x be the number of years after 2010.

We have been given a population of fish in a lake is 14000 in 2010. The population decreases 6% annually.

We can see that population of fish is the lake is decreasing exponentially as it is decreasing 6% annually.

Since we know that an exponential function is in form: $y=a*b^x$ , where,

a = Initial value,

b = For decrease or decay b is in form (1-r) where r represents decay rate in decimal form.

Let us convert our given decay rate in decimal form.

$6\5=\frac{6}{100}=0.06$

Upon substituting our given values in exponential form of function we will get the population of fish in the lake after x years as:

$y=14,000*(1-0.06)^x$

$y=14,000*(0.94)^x$

Let us find x by subtracting 2010 from 2019.

$x=2019-2010=9$

Upon substituting x=9 in our function we will get,

$y=14,000*(0.94)^9$

$y=14,000*0.5729948022286167$

$y=8021.927\approx 8022$

Therefore, the population of fish in 2019 will be 8022.

6 0

3 years ago

You make and sell triangular flags. Each flag has a base of 3.5 feet and a height of 2.5 feet. Fabric for the flags costs $0.40

AlexFokin [52]

Answer:

Square feet refer to the area of the triangle. Using the area formula (1/2bh), the area is calculated to be 4.375 square feet. If each square foot costs $.40 to make, then the correct process is to multiply 4.375 by .40, making the correct answer $1.75.

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

2,776,714 rounded to the greatest place value is?How many zeros are in the rounded number?The estimated speed of light using a p

Simora [160]

Answer:

3,000,000. 6 Zeros. 898,752,432,640

299,792 kilometers per second is the speed of light normally

Step-by-step explanation:

7 0

3 years ago

Someone please help!!!!!

Nadya [2.5K]

Answer:

144 people were originally at the party.

Step-by-step explanation:

18 boys is one fifth of the second boys population, so the second population is 18x9 = 162. The original population would be 162-18, which equals 144.

6 0

3 years ago