What is the solution of the system of equations?

3x + 6y = - 2

15x + 30y = - 10

You would have to multiply either equation in order to get one of the variables to cancel.

I would multiply the first equation by - 5.

-5 (3x + 6y = - 2)

-15x - 30y = 10

15x + 30y = - 10

0 + 0 = 0

Since everything cancels and the equation is true, the solution is Infinitely many solutions, or all real numbers.