Question

Answer 1

(2x - 1)² + (x + 1)² + 2(2x - 1)(x + 1) - 1

= (2x - 1 + x + 1)² - 1

= (3x)² - 1

= 9x² - 1

Answer 2

\(\left(2x-1\right)^2+\left(x+1\right)^2+2\left(2x-1\right)\left(x+1\right)-1\)
\(=\left(2x-1\right)^2+2\left(2x-1\right)\left(x+1\right)+\left(x+1\right)^2-1\)
\(=\left(2x-1+x+1\right)^2-1\)
\(=\left(3x\right)^2-1\)
\(=9x^2-1\)

Answer 3

(2x - 1)² + (x + 1)² + 2(2x - 1)(x + 1) - 1

= (2x - 1 + x + 1)² - 1

= (3x)² - 1

= 9x² - 1

gửi bn