How do you factor 5a^2 + 10ab - 15b^2?

2 Answers
May 27, 2015

y = 5(a^2 + 2ab - 3b^2)

= 5(a - b)(a + 3b)

Check: y = 5(a^2 + 3ab - ab - 5b) . OK

May 27, 2015

To factor 5a^2+10ab-15b^2
first extract the obvious common constant factor
then look for factors of the simplified variable term

5a^2+10ab-15b^2
= 5(a^2+2ab-3b^2)

=5(a+3b)(a-b)