Question

(a+2b)^2
.............

Answer 1

a^2 +4ab+4b^2

Explanation:

(a+2b)^2

(a+2b)(a+2b)

FOIL

first: a*a = a^2

outer: a*2b = 2ab

inner: 2b*a = 2ab

last: 2b*2b = 4b^2

Add them together

a^2 +2ab+2ab+4b^2

Combine like terms

a^2 +4ab+4b^2

Answer 2

Solution given:

(a+2b)²

we have

by using formula

(a+b)²=a²+2ab+b²

so

we get

a²+2*a*2b+(2b)²

=a²+4ab+4b²