Question

Answer 1

BT2:

\(A=\left(x+y\right)^2-\left(x-y\right)^2\)

\(A=\left[\left(x+y\right)-\left(x-y\right)\right]\left[\left(x+y\right)+\left(x-y\right)\right]\)

\(A=\left(x+y-x+y\right)\left(x+y+x-y\right)\)

\(A=2y.2x\)

\(A=4xy\)

\(B=\left(x+y\right)^2-2\left(x+y\right)\left(x-y\right)+\left(x-y\right)^2\)

\(B=\left[\left(x+y\right)-\left(x-y\right)\right]^2\)

\(B=\left(x+y-x+y\right)^2\)

\(B=\left(2y\right)^2\)

\(B=4y^2\)

Answer 2

3:

a: A=(153+47)^2=200^2=40000

b: B=(126-76)^2=2500