Solve this system of equations using elimination (Show your work).

3x+6y=18
3x+y=-7

Show work

1. Multiply the second equation by 6 to make the coefficients of x in both equations cancel when added together:

6(3x + y) = 6(-7)
18x + 6y = -42

2. Now we have:

3x + 6y = 18
18x + 6y = -42

3. Subtract the first equation from the second equation to eliminate y:

18x + 6y - (3x + 6y) = -42 - 18
15x = -60
x = -4

4. Substitute x = -4 back into one of the original equations to solve for y. Let's use the first equation:

3(-4) + 6y = 18
-12 + 6y = 18
6y = 30
y = 5

Therefore, the solution to the system of equations is x = -4 and y = 5.