Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Thợ Đào Mỏ Panda, mày bị điên à, không biết còn trả lời làm cái quái gì
a) x3-2x2-x+2
=x(x2-1)+2(-x2+1)
=x(x2-1)-2(x2-1)
=(x2-1)(x-2)
b)
x2+6x-y2+9
=x2+6x+9-y2
=(x+3)2-y2
=(x+3-y)(x+3+y)
\(2x^4+x^3-6x^2+x+2\)
= \(2x^4+4x^3-3x^3-6x^2+x+2\)
= \(2x^3\left(x+2\right)-3x^2\left(x+2\right)+\left(x+2\right)\)
= \(\left(x+2\right)\left(2x^3-3x^2+1\right)\)
=\(\left(x+2\right)\left(2x^3-2x^2-x^2+1\right)\)
=\(\left(x+2\right)\left(2x^2\left(x-1\right)-\left(x+1\right)\left(x-1\right)\right)\)
=\(\left(x+2\right)\left(x-1\right)\left(2x^2-x-1\right)\)
= \(\left(x+2\right)\left(x-1\right)\left(2x^2-2x+x-1\right)\)
=\(\left(x+2\right)\left(x-1\right)\left(2x\left(x-1\right)+\left(x-1\right)\right)\)
=\(\left(x+2\right)\left(2x+1\right)\left(x-1\right)^2\)
\(=x\left(2x^2-x-6\right)\)
\(=x\left(2x^2-4x+3x-6\right)\)
\(=x\left[2x\left(x-2\right)+3\left(x-2\right)\right]\)
\(=x\left(x-2\right)\left(2x+3\right)\)
x(2x^2-x-6)
x(2x^2-4x+3x-6)
x[2x(x-2)+3(x-2)]
x(2x+3)(x-2)
2x2 - 2y2 - 6x - 6x = 2(x2 - y2) - 6(x + y) = 2(x - y)(x + y) -2.3.(x + y) = 2(x + y)[(x - y) - 3] = 2(x + y)(x - y - 3)
( x2 - 3x )2 + ( 2x2 - 6x ) - 24
= ( x2 - 3x )2 + 2( x2 - 3x ) - 24 (*)
Đặt t = x2 - 3x
(*) trở thành :
t2 + 2t - 24
= t2 - 4t + 6t - 24
= t( t - 4 ) + 6( t - 4 )
= ( t - 4 )( t + 6 )
= ( x2 - 3x - 4 )( x2 - 3x + 6 )
= ( x2 + x - 4x - 4 )( x2 - 3x + 6 )
= [ x( x + 1 ) - 4( x + 1 ) ]( x2 - 3x + 6 )
= ( x + 1 )( x - 4 )( x2 - 3x + 6 )
\(\left(x^2-3x\right)^2+\left(2x^2-6x\right)-24\)
\(=\left(x^2-3x\right)^2+2\left(x^2-3x\right)-24\)(1)
Đặt \(a=x^2-3x\)
(1)=\(a^2+2a-24\)
\(=a^2-4a+6a-24\)
\(=a\left(a-4\right)+6\left(a-4\right)\)
\(=\left(a-4\right)\left(a+6\right)\)
\(=\left(x^2-3x-4\right)\left(x^2-3x+6\right)\)
\(=\left(x^2-4x+x-4\right)\left(x^2-3x+6\right)\)
\(=\left[x\left(x-4\right)+\left(x-4\right)\right]\left(x^2-3x+6\right)\)
\(=\left(x+1\right)\left(x-4\right)\left(x^2-3x+6\right)\)
x3 + 2x2 - 6x - 27
= (x3 - 3x2) + (5x2 - 15x) + (9x - 27)
= x2(x - 3) + 5x(x - 3) + 9(x - 3)
= (x - 3)(x2 + 5x + 9)
\(=2x\left(x-3\right)\)
\(2x^2-6x=2x\left(x-3\right)\)