How do you multiply (5b - 3) ( 3b - 5)?

1 Answer
Apr 24, 2018

15b^s -34b-15

Explanation:

Let's say 5b is a, -3 is b, 3b is c and -5 is d
We always have to multiply a by c, then a by d, then b by c, then b by d.
AKA ac, ad, bc, bd
ac would equal 5b * 3b , which is equal to 15b^2.

ad would equal 5b * -5 , which is equal to -25b

bc would equal 3b *-3 , which is equal to -9b

bd would equal -3*-5 , which is equal to -15

Add 'em all together and you get 15b^2 -25b-9b-15.
Simplify and you get 15b^s -34b-15