Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(x^8+3x^4+4\)
\(=\left(x^8-x^6+2x^4\right)+\left(x^6-x^4+2x^2\right)+\left(2x^4-2x^2+4\right)\)
\(=x^4\left(x^4-x^2+2\right)+x^2\left(x^4-x^2+2\right)+2\left(x^4-x^2+2\right)\)
\(=\left(x^4+x^2+2\right)\left(x^4-x^2+2\right)\)
\(4x^4+4x^3+5x^2+2x+1\)
\(=\left(4x^4+2x^3+2x^2\right)+\left(2x^3+x^2+x\right)+\left(2x^2+x+1\right)\)
\(=2x^2\left(2x^2+x+1\right)+x\left(2x^2+x+1\right)+\left(2x^2+x+1\right)\)
\(=\left(2x^2+x+1\right)^2\)
a) x2 + 6x + 9 = x2 + 2 . x . 3 + 32 = (x + 3)2
b) 10x – 25 – x2 = -(-10x + 25 +x2) = -(25 – 10x + x2)
= -(52 – 2 . 5 . x – x2) = -(5 – x)2
c) 8x3 - 1/8 = (2x)3 – (1/2)3 = (2x - 1/2)[(2x)2 + 2x . 12 + (1/2)2]
= (2x - 1/2)(4x2 + x + 1/4)
d)1/25x2 – 64y2 = (1/5x)2(1/5x)2- (8y)2 = (1/5x + 8y)(1/5x - 8y)
x3 + x2 + 4
= x3 + 2x2 - x2 - 2x + 2x + 4
= x2(x + 2) - x(x + 2) + 2(x + 2)
= (x + 2)(x2 - x + 2)
2x3 - 3x2 + 3x - 1
= 2x3 - x2 - 2x2 + x + 2x - 1
= 2x2(x - 1/2) - 2x(x - 1/2) + 2(x - 1/2)
= (x - 1/2)(2x2 - 2x + 2)
= 2(x - 1/2)(x2 - x + 1)
3x3 - 14x2 + 4x + 3
= 3x3 + x2 - 15x2 - 5x + 9x + 3
= 3x2(x + 1/3) - 15x(x + 1/3) + 9(x + 1/3)
= (x + 1/3)(3x2 - 15x + 9)
= 3(x + 1/3)(x2 - 5x + 3)
x6+3x4y2-8x3y3+3x2y4+y6= x6+3x4y2+3x2y4+y6-8x3y3=(x2+y2)3-(2xy)3
= (x2+y2-2xy)[(x2+y2)2+2xy(x2+y2)+(2xy)2]= (x-y)2(x4+6x2y2+y4+2x3y+2xy3)
(x2+y2-5)2-4x2y2-16xy-16=(x2+y2-5)2-(4x2y2+16xy+16)=(x2+y2-5)2-(2xy+4)2
=(x2+y2-5+2xy+4)(x2+y2-5-2xy-4)=(x2+2xy+y2-1)(x2-2xy+y2-9)=[(x+y)2-1][(x-y)2-32]=(x+y-1)(x+y+1)(x-y-3)(x-y+3)
x4+324=x4+36x2+324-36x2=(x2+18)2-(6x)2=(x2+18-6x)(x2+18+6x)
Đặt x2 + 4x + 8 = A. Ta sẽ được:
A2 + 3xA + 2x2
= A2 - xA - 2xA + 2x2
= A(A-x) - 2x(A-x)
= (A-x)(A-2x)
= (x2+3x+8)(x2+2x+8)
\(x^5-2x^4+3x^3-4x^2+2\)
\(=x^5-x^4-x^4+x^3+2x^3-2x^2-2x^2+2x-2x-2\)
\(=\left(x^5-x^4\right)-\left(x^4-x^3\right)+\left(2x^3-2x^2\right)-\left(2x^2-2x\right)-\left(2x-2\right)\)
\(=x^4\left(x-1\right)-x^3\left(x-1\right)+2x^2\left(x-1\right)-2x\left(x-1\right)-2\left(x-1\right)\)
\(=\left(x-1\right)\left(x^4-x^3+2x^2-2x-2\right)\)
=x . x .x .x .x-x.x.x.x.x.x.x.x+x.x.x.x.x.x.x.x.x-x.x.x.x.x.x.x.x+2