Question

bài 1 : rút gọn

A = ( 2x + 1)² + 2( 4x² - 1) + ( 2x - 1 )²

B = x( x - 4 )(x+ 4 ) -( x² + 1)(x² - 1)

C = ( x² - 1 ) ( x - 3 ) - ( x - 3 )( x² + 3x + 9 )

bài 2 : phân tích

a, x² + 4y² - 2x +4xy - 4y

b, ( x + 2 )( x + 3 )( x+ 4 )( x+ 5 ) - 24

tks trc nha ! _ove

Answer 1

B1:

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

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

A = \(16x^2\)

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

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

B = \(x^3-16x-x^4+1\)

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

C = \(x^3-3x^2-x+3-x^3+27\)

C = \(-3x^2-x+30\)