Final answer:
To solve the system of equations by elimination, we multiply the equations to eliminate a variable, subtract the equations to solve for the other variable, and substitute the value back to find the solution.
Step-by-step explanation:
To solve the system of equations by elimination, we need to eliminate one of the variables by adding or subtracting the equations. In this case, we can eliminate the variable m by multiplying the first equation by 5 and the second equation by 3. This will give us:
15m + 20n = -65
15m + 18n = -57
Now, subtracting the second equation from the first equation, we get:
15m + 20n - (15m + 18n) = -65 - (-57)
2n = -8
Dividing both sides by 2, we find that n = -4.
Now, substituting this value of n into one of the original equations, we can solve for m:
3m + 4(-4) = -13
3m - 16 = -13
3m = 3
m = 1.
Therefore, the solution to the system of equations is m = 1 and n = -4.