solve the following algebra problem

Question

Solve the system by substitution

 

3x - 6y = 15

2x + 8y = -2

Answer 1

3x-6y=15

2x+8y=-2

simplify each equation

divide first equation by 3

x-2y=5

divide second equation by 2

x+4y=-1

now you have...

x-2y=5

x+4y=-1

using substitution, use either equation to isolate x

x=2y+5

substitute

2y+5+4y=-1

6y+5=-1

6y=-5-1

6y=-6

y=-1

find x by substituting y=-1 into either equation

x+4(-1)=-1

x-4=-1

x=4-1

x=3

x=3 and y=-1