Question

Solve each system by elimination. -4x + 8y = -24 7x - 5y = 24

Answer 1

Answer:

The solution is the point (2,-2)

Step-by-step explanation:

we have

$-4x+8y=-24$ -----> equation A

$7x-5y=24$ -----> equation B

step 1

Multiply by 7 equation A both sides

$7(-4x+8y)=7(-24)$

$-28x+56y=-168$ -----> equation C

step 2

Multiply equation B by 4 both sides

$4(7x-5y)=4(24)$

$28x-20y=96$ -----> equation D

step 3

Adds equation C and equation D

$-28x+56y=-168\\28x-20y=96\\-----------\\56y-20y=-168+96\\36y=-72\\y=-2$

Find the value of x

substitute the value of y in any equation

equation A

$-4x+8(-2)=-24\\4x=-16+24\\4x=8\\x=2$

therefore

The solution is the point (2,-2)