Question

Rút gọn

(2x +1) ²+2(4x²-1) +(2x-1) ²

^{trả lời nhanh giúp mk đúng mk tick nha}

Answer 1

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

\(=\left(2x+1+2x-1\right)^2=\left(4x\right)^2=16x^2\)

Answer 2

Ta thấy: Biểu thức trên có dạng \(\left(a+b\right)^2=a^2+2ab+b^2\)

Áp dụng vào ta có: \(\left(2x+1\right)^2+2\left(4x^2-1\right)+\left(2x-1\right)^2\)

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

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

                          \(=4x^2=\)

Answer 3

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

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

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

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

\(=\left[\left(2x+1\right)+\left(2x-1\right)\right].\left[\left(2x+1\right)-\left(2x-1\right)\right]+2\left(2x+1\right)\left(2x-1\right)\)

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

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