Question

Help...
Multiply the binomials:
(0.4a+0.5b)(0.4a-0.5b)

Answer 1

use the FOIL rule. that is. First, outside, inside, last. this means you first multiply the .4a terms, then the outermost terms .4a and .5b..... ect

Answer 2

try it and tell me what you get.

Answer 3

I got 0.8a^2-0.2ab+0.2ab-0.25b^2 then I added like terms and that got rid of the "ab" terms. My end result was 0.8a^2-0.25b^2

Answer 4

Okay I figured out what I did. I added instead of multiplying the 0.4's. Got .16a^2-0.25b^2 now.