Question

Does anyone understand this:
it's in the link

Answer 1

\[a ^{2}-b ^{2}=\left( a+b \right)\left( a-b \right)\]

Answer 2

its B ...

Answer 3

wait so (x+1) * (x+1) first?

Answer 4

like, which is a and which is b?

Answer 5

a=x+1

Answer 6

wait so (x+1)^2= x^2+2x+1 right?

Answer 7

don't we do that first?

Answer 8

like I don't understand your first equation:
a2−b2=(a+b)(a−b)

Answer 9

very simple here a=x+1,b=y
\[\left( x+1 \right)^{2}-y ^{2}=\left( x+1+y \right)\left( x+1-y \right)\]

Answer 10

wait, why + y?

Answer 11

wait ohhh, ohh, ok I see now, thank-you

Answer 12

wait wait wait

Answer 13

actually yeah, why is there a +y?

Answer 14

oh, nevermind

Answer 15

\[(a+b)(a-b)=a \left( a-b \right)+b \left( a-b \right)=a ^{2}-ab+ab-b ^{2}=a ^{2}-b ^{2}\]