8a^2 + 40ab+ 50b^2 = 2(4a^2 +20ab +25b^2)

Question

= 2(2a + 5b)^2
How is this a perfect square?

Answer 1

are you referring to
http://www.jiskha.com/display.cgi?id=1279063490 ?

Do not start a new thread, keep replying to the original.

As to your question, expand

(2a + 5b)^2 using FOIL