Question

Expand the brackets and collect terms:
(X+2)^2 - (X+1)^2

I worked it out to be 1x + 3, but the answer book says 2x + 3, can anyone explain please?

Answer 1

\((x+2)^2=(x+2)(x+2)\)
FOIL that out for me.

Answer 2

FOIL?

Answer 3

\(\color{red}{\text{FOIL}}\)
\(\color{red}{\text{F}}\text{irst}\)
\(\color{red}{\text{O}}\text{uter}\)
\(\color{red}{\text{I}}\text{nner}\)
\(\color{red}{\text{L}}\text{ast}\)

\((a+b)(c+d)=ac+ad+bc+bd\)

Answer 4

Ah right, I'm with you, thanks a lot.

Answer 5

No problem :)