Question

Solve by factoring:
One of the solutions to the quadratic equation x^2 - 13x + 30 is 3.
What is the other solution?

Answer 1

(x-_)(x-_) minus signs because that's the only way to get the last number + and the cross term negative. to determine the last two numbers just find which two numbers multiply to give 30 and add to give 13:
3 and 10, so the other answer is 10. the factoring would be (x-10)(x-3)