Question

Which ordered pair is the solution to the system of equations? PLS HELP

−3x+4y=−20y=x−4

(4, 8)
(0, −5)
(−2, −6)
(−4, −8)

Answer 1

The correct answer is (−4, −8)

Explanation:

You have to substitute!!! :)

−3x + 4y = −20 y = x − 4

-3(4) + 4(8) = -20 8 = 4 - 4

-12 + 32 = -20 8 = 0

20 = 20

−3x + 4y = −20 y = x − 4

-3(0) + 4(-5) = -20 -5 = 0 - 4

0 + 20 = -20 -5 = -4

20 = -20

−3x + 4y = −20 y = x − 4

-3(-2) + 4(-6) = -20 -6 = -2 - 4

6 - 24 = -20 -6 = -6

-18 = -20

−3x + 4y = −20 y = x − 4

-3(-4) + 4(-8) = -20 -8 = -4 - 4

12 - 32 = -20 -8 = -8

-20 = -20

Answer 2

(-4,-8)

Explanation:

This a system of equation that have two variables x and y and we have two equations that we have to solve simultaneously

−3x+4y=−20 ....(1)

y=x−4 ....(2)

We can substitute equation (2) and (1)

-3x+4y = −20

-3x+4(x−4) = −20

-3x + 4x -16 = -20

x = -4

Now we need to find the value of y

y=x−4 = -4 - 4 = -8

(-4,-8)