Final answer:
To solve the system by substitution, substitute the expression from the first equation (-3x = y) into the second equation (-9x - 5y = -48) to find x = -8.
Then, substitute x back into the first equation to find y = 24.
Step-by-step explanation:
Step-by-Step Solution for the System by Substitution
The first equation given is -3x = y,
which we can rearrange as y = -3x.
Looking at the second equation, -9x - 5y = -48, we can now substitute the expression for y from the first equation into this second one.
Substituting y we get: -9x - 5(-3x) = -48.
This simplifies to -9x + 15x = -48.
Combining like terms gives us 6x = -48.
Dividing by 6, we find x = -8.
Now that we have x, we can find y by substituting x back into the first equation, y = -3(-8),
which gives us y = 24.
So, the solution to the system of equations by substitution is x = -8 and y = 24.