Question

Factor completely.

-5x²y + 10xy - 15xy²

a) -5xy(x + 2 + 3y)
b) -5xy(x - 2 + 3y)
c) 5xy(-x + 2 + 3y)

Answer 1

Start by looking for common factors. All the coefficients are multiples of 5 and there are at least one x and one y in each term. So you will be able to factor out 5xy from each term. When you do that, what do you have left?

Answer 2

Or, try expanding each answer by mutiplying the terms, and see which one give you the starting equation.