Question

solve by substitution
r+s=-12
4r-6s=12

Answer 1

1. Solve for either variable in the first equation
2. Substitute that information into the second equation

Answer 2

S=12-r so use this to substitute into the equation 4r-6s=12

So you would get 4r-6(12-r)=12

Distribute the 6(12-r) you get 72-6r
Your equation should look like: 4r-72+6r=12
Add like terms.
Now your equation is 10r-72=12
Add 72 to both sides
10r=84
r=8.4

Now fill 8.4 into the first equation to get the s.

8.4+s=-12

subtract 8.4

s=-20.4