Solve by Substitution 8x-6y=-20 , -16x+7y=30

Problem

{[8*x−6*y=−20],[−16*x+7*y=30])

Solution

1. Isolate the variable x in the first equation by adding 6*y to both sides and then dividing by 8

8*x=6*y−20

x=(6*y−20)/8

x=0.75*y−2.5

2. Substitute the expression for x into the second equation.

−16*(0.75*y−2.5)+7*y=30

3. Distribute the −16 and combine like terms to solve for y

−12*y+40+7*y=30

−5*y+40=30

−5*y=−10

y=2

4. Substitute the value of y back into the expression for x

x=0.75*(2)−2.5

x=1.5−2.5

x=−1

Final Answer

(x,y)=(−1,2)

Want more problems? Check here!