Question

Rút gọn biểu thức :

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

Answer 1

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

Answer 2

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

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

=\(8x^2+2-8x^2+2\)

=4

Answer 3

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

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

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