a) x2 + 4x + 3
= x2 + 3x + x +3
= ( x2 + 3 ) + ( x + 3 )
= x ( x + 3 ) + ( x + 3 )
= ( x + 3 ) ( x + 1 )
b) 4x2 - 4x - 3
= 4x2 + 2x - 6x - 3
= ( 4x2 + 2x ) - ( 6x + 3 )
= 2x ( 2x + 1 ) - 3 ( 2x + 1 )
= ( 2x + 1 )( 2x - 3 )
c) x2 - x - 12
= x2 + 3x - 4x - 12
= ( x2 + 3x ) - ( 4x + 12 )
= x ( x + 3 ) - 4 ( x + 3 )
= ( x + 3 ) ( x - 4 )
d) 4x4 - 4x2y2 - 8y4
= 4 ( x4 - x2y2 - 2y4 )
Hk tốt
a) \(x^2+4x+3\)
= \(x^2+x+3x+3\)
= \(x\left(x+1\right)+3\left(x+1\right)\)
= \(\left(x+1\right)\left(x+3\right)\)
b) \(4x^2-4x-3\)
= \(4x^2+2x-6x-3\)
= \(2x\left(x+1\right)-3\left(x+1\right)\)
= \(\left(x+1\right)\left(2x-3\right)\)
c)\(x^2-x-12\)
= \(x^2-4x+3x-12\)
= \(x\left(x-4\right)+3\left(x-4\right)\)
= \(\left(x-4\right)\left(x+3\right)\)
câu d la 4x^2.y^2 phai ko
\(4x^4-4x^2y^2-8y^4\)
= \(4x^4-8x^2y^2+4x^2y^2-8y^4\)
= \(4x^2\left(x^2-2y^2\right)+4y^2\left(x^2-2y^2\right)\)
= \(\left(4x^2+4y^2\right)\left(x^2-2y^2\right)\)
=\(4\left(x^2+y^2\right)\left(x^2-2y^2\right)\)
Kết bạn với mình nha
Phạm Kim Cương dòng 3 phần a nhầm xíu nha
Làm lại phần d)
4x4-4x2y2-8y4=4((x4-2x2y2)+(x2y2-2y4))=4(x2(x2-2y2)+y2(x2-2y2))=4(x2+y2)(x2-2y2)
\(x^2-x-12\)
\(=x^2+3x-4x-12\)
\(=x\left(x+3\right)-4\left(x+3\right)\)
\(=\left(x+3\right)\left(x-4\right)\)
