Question

Answer 1

1) \(\left(x-2\right)\left(x+2\right)-\left(x-2\right)^2=x^2-4-x^2+4x-4=4x-8\)

2) \(\left(5x+2\right)^2+\left(5x-3\right)^2-2\left(5x+2\right)\left(5x-3\right)=\left(5x+2-5x+3\right)^2=5^2=25\)

Answer 2

1/ =(x-2).(x+2-x+2)                     2/ =(5x+2)^2 -2(5x+2)(5x-3) +(5x-3)^2

    =4.(x-2)                                      =(5x+2-5x+3)^2=5^2=25

Answer 3

1: \(\left(x-2\right)\left(x+2\right)-\left(x-2\right)^2\)

\(=x^2-4-x^2+4x-4\)

=4x-8

2: Ta có: \(\left(5x+2\right)^2-2\left(5x+2\right)\left(5x-3\right)+\left(5x-3\right)^2\)

\(=\left(5x+2-5x+3\right)^2\)

=25