Question

In the following system of equations, if the first equation is multiplied by 3, what would the second equation need to be multiplied by to eliminate y by the addition?

3x + 5y = 10
4x - 3y = 12

Answer 1

You have 5y in the fist equation and are multiplying that by 3, which means you will have 15y. In order to eliminate that with the 2nd equation, you'll need to have -15y. You have -3y.

so -3y * x = -15y

solve for x.