Question #f621d

1 Answer
Jan 20, 2018

If p+q=4, then y can take any value. Otherwise, y=0.

Explanation:

It's a bit weird for the problem to ask to "solve for y" because if we tried to do so, we'd get "y=0, provided p+q!=4" without a way to express y in terms of p,q...anyway,

we have py+qy=-4y+8y. Let's factor out y from both sides to make things simpler:

(p+q)y=4y. Then we can subtract 4y from both sides, and factor out y again from the left:

(p+q-4)y=0.

This is true either when p+q=4, in which case y can be anything, or when y=0.