How do you solve the following system: -29=5y-3x, 5x+2y=12 ?

1 Answer
Mar 22, 2018

x = 118/31 and y = -109/31

Explanation:

We can eliminate a variable by subtracting out an equation.

For example, let's take 3 times the second plus five times the first:

3(5x+2y = 12) implies 15x + 6y = 36
5(-3x + 5y = -29) implies -15x + 25y = -145
Adding them together,
31y = -109 implies y = (-109)/31

We can now plug this into our second equation from before and get x:
5x + 2((-109)/31) = 12 implies 5x = 12 + 218/31 = 590/31
x = 118/31

Thus we have our answer.