Question

rút gọn biểu thức: 

a) (x+2)^2+4(x+2)(x-2)+(x-4)^2

giúp mính với ạ

Answer 1

\(\left(x+2\right)^2+4\left(x+2\right)\left(x-2\right)+\left(x-4\right)^2\\ =x^2+4x+4+4x^2-16+x^2-8x+16\\ =6x^2-4x+4\)

Answer 2

(x + 2)² + 4(x + 2)(x - 2) + (x - 4)²

<=> x² + 4x + 4 + 4(x² - 4) + x² - 8x + 16

<=> x² + 4x + 4 + 4x² - 16 + x² - 8x + 16

<=> x² + 4x² + x² + 4x - 8x + 4 - 16 + 16

<=> 6x² - 4x + 4

Answer 3

a: Ta có: \(\left(x+2\right)^2+4\left(x+2\right)\left(x-2\right)+\left(x-4\right)^2\)

\(=x^2+4x+4+4x^2-16+x^2-8x+16\)

\(=6x^2-4x+4\)