Question

6x + y = -39 3x + 2y = -15 elimination using multiplication

Answer 1

Multiply the second equation by 2 so that its 
6x+4y=-30
then subtract 
6x+y=-39
6x+4y=-30
= -3y=-69
divide by -3 to isolate the y
then you get y=23
substitute the y value back into one of the equations to solve for x.
6x+23=-31
solve like you always do and you'll get your x
Congratulations, you solved a problem.