How do you expand (b+2)^2 ?

#(b+2)^2#

3 Answers
Mar 8, 2018

#b^2 + 4b + 4#

Explanation:

This is a binomial squared.

#(a+b)^2 = a^2 + 2ab + b^2#

Hence:

#(b+2)^2 = b^2 + 2(b)(2) + 2^2 = b^2 + 4b + 4#

Mar 8, 2018

I believe it would be #b^2 + 4b + 4#

Explanation:

#(x+y)^2# would be #x^2+2xy+y^2#
You have to square the first two and combine for the middle figure

Mar 8, 2018

This uses FOIL, or First, Outer, Inner, Last expansion. After writing out the square (value of parenthesis twice), we expand. For your problem, I got #b^2+4b+4#.

Explanation:

#=(b+2)^2#
#=(b+2)(b+2)#

FOIL is found by multiplying each term to each other. Our objective is to end up in a simplified form.

First;#= b*b=b^2#
Outer;#= b*2=2b#
Inner;#=2*b=2b#
Last;#=2*2=4#

We end up with #b^2 + 2b +2b +4#

This isn't simplified completely, however. Don't forget to combine like terms. Like terms in this is 2b and 2b.

End result? #b^2+4b+4#