Question

solve the system by substitution
1.) 6x-8y=-16
x+y=-5
2.) y=7x+14
y= 7x+14
Solve the system by elimination
3.) x-3y=14
-7x+9y=-14
4.) -7x-7y=-7
8x+8y=8

Answer 1

The first step in substitution is to isolate the variable. for example one pick one of the variable to isolate.
x=y-5

Answer 2

Then you plug in that expression into the equation and solve
6(y-5) + 8y =16

Answer 3

14y-30=16

Answer 4

14y=46

Answer 5

y=7/23

Answer 6

next you plug that value into the original equation and find the other variable

Answer 7

By this you are substituting the values

Answer 8

Didn't see the negative

Answer 9

(-6,1) is your answer