Question

Rút Gọn

a) (x+2)(x-2)-(x-3)(x+1)
b) (2x+1)^2+(3x-1)^2+2.(2x+1)(2x-1)

 

Answer 1

a) \(\left(x+2\right)\left(x-2\right)-\left(x-3\right)\left(x+1\right)\)

\(=\left(x^2-4\right)-\left(x^2-2x-3\right)\)

\(=x^2-4-x^2+2x+3\)

\(=2x-1\)

Answer 2

a) (x + 2)(x - 2) - (x - 3)(x + 1)

= x² - 4 - x² + 2x + 3

= 2x - 1

b) (2x + 1)² + (3x - 1)² + 2.(2x + 1)(2x - 1)

= 4x² + 4x + 1 + 9x² - 6x + 8x² - 2 

= 21x² - 2x

Answer 3

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

\(=\left(4x^2+4x+1\right)+\left(9x^2-6x+1\right)+2\left(4x^2-1\right)\)

\(=4x^2+4x+1+9x^2-6x+1+8x^2-2\)

\(=21x^2-2x\)

Answer 4

a) \(\left(x+2\right).\left(x-2\right)-\left(xx-3\right).\left(x+1\right)\)

\(=\left(x^2-4\right)-\left(x^2-2x-3\right)\)

\(=x^2-4-x^2+2x+3\)

\(=2x-1\)

b) \(\left(2x+1\right)^2+\left(3x-1\right)^2+2\left(2x+1\right).\left(2x-1\right)\)

\(=\left(4x^2+4x+1\right)+\left(9x^2-6x+1\right)+8x^2-2\)

\(=21x^2-2x\)

Rất vui vì giúp đc bạn <3