x^3 - 2x^2y - 4x +8y
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
9 tháng 3 2018
a) \(\left(3x+y-z\right)-\left(4x-2y+6z\right)\)
\(=3x+y-z-4x+2y-6z\)
\(=-x+3y-7z\)
b) \(\left(x^3+6x^2+5y^3\right)-\left(2x^3-5x+7y^3\right)\)
\(=x^3+6x^2+5y^3-2x^3+5x-7y^3\)
\(=-x^3+6x^2+5x-2y^3\)
c) \(\left(5,7x^{2y}-3,1xy+8y^3\right)-\left(6,9xy-2,3x^{2y}-8y^3\right)\)
\(=5,7x^{2y}-3,1xy+8y^3-6,9xy+2,3x^{2y}+8y^3\)
\(=8x^{2y}-10xy+16y^3\)
TN
1
1 tháng 7 2021
9) (x^2 + 2/5y) (x^2 - 2/5y)
= (x^2)^2 + 2^2/(5y)^2
= x^4 + 4/25y^2
10) (x/2 - y) (x/2 + y)
= x^2/2^2 - y^2
= x^4/4 - y^4
11) (x/2 - 2y)^2
= (x/2)^2 - 2.x/2.2 + (2y)^2
= x/4 - 2x + 4y
12) (√2x - y)^2
= (√2x)^2 - 2.√2x.y + y^2
= 2x^2 - 2√2xy + y^4
13) (3/2x + 3y)^2
= (3/2x)^2 + 2.3/2x.3y + (3y)^2
= 9/4x^2 + 9xy + 9y^2
14) (√2x + √8y)^2
= (√2x)^2 + 2.√2.√8 + (√8y)^2
= 2x^2 + 2√2√8 + 9y^2
6 tháng 8 2021
a, \(x-2y+x^2-4y^2=\left(x-2y\right)+\left(x-2y\right)\left(x+2y\right)=\left(x-2y\right)\left(1+x+2y\right)\)
b, \(x^2-4x^2y^2+y^2+2xy=\left(x+y\right)^2-\left(2xy\right)^2\)
\(=\left(x+y-2xy\right)\left(x+y+2xy\right)\)
c, \(x^6-x^4+2x^3+2x^2=x^6+2x^3+1-x^4+2x^2-1\)
\(=\left(x^3+1\right)^2-\left(x^2-1\right)^2=\left(x^3-x^2+2\right)\left(x^3+x^2\right)\)
\(=x^2\left(x+1\right)\left(x^3-x^2+2\right)\)
d, \(x^3+3x^2+3x+1-8y^3=\left(x+1\right)^3-\left(2y\right)^3=\left(x+1-2y\right)\left(x+1+2y\right)\)
6 tháng 8 2021
a) Ta có: \(x-2y+x^2-4y^2\)
\(=\left(x-2y\right)+\left(x-2y\right)\left(x+2y\right)\)
\(=\left(x-2y\right)\left(1+x+2y\right)\)
b: Ta có: \(x^2-4x^2y^2+y^2+2xy\)
\(=\left(x+y\right)^2-\left(2xy\right)^2\)
\(=\left(x+y-2xy\right)\left(x+y+2xy\right)\)
TN
0
11 tháng 8 2023
`a,-x^3/8 + 3/(4x^2) - 3/(2x) +1`
`=-(x^3/8 - 3/(4x^2) + 3/(2x) - 1)`
`=-(x/2 - 1)^3`
`b,x^6 - 3/(2x^{4} y) + 3/(4x^{2}y^{2}) - 1/(8y^{3})`
`=(x^3 - 1/(2y))^{3}`
8 tháng 7 2016
P= 125x^3-8y^3
=5^3x^3-2^3y^3
=(5x)^3-(2y)^3
=(5x-2y)(25x^2+10xy+4y^2)
P=4x(x-2y)+8y(2y-x)
=4x(x-2y)-8y(x-2y)
=(4x-8y)(x-2y)
=4(x-2y)(x-2y)
=4(x-2y)^2
(2x+1)^2-(x-1)^2=(2x+1-x+1)(2x+1+x-1)
=(x+2)3x
K NHA!
DT
1
3 tháng 3 2018
Xét \(pt(2):\) \(\left(2x+4y-1\right)\sqrt{2x-y-1}=\left(4x-2y-3\right)\sqrt{x+2y}\)
\(\Leftrightarrow\left(2x+4y-1\right)^2\left(2x-y-1\right)-\left(4x-2y-3\right)^2\left(x+2y\right)=0\)
\(\Leftrightarrow-8x^3+12x^2y+12x^2+44xy^2+8xy-3x-24y^3-32y^2-11y-1=0\)
\(\Leftrightarrow-\left(x-3y-1\right)\left(8x^2+12xy-4x-8y^2-8y-1\right)=0\)
\(\Rightarrow x=3y+1\) thay vào \(pt(1)\) ta có
\(pt\left(1\right)\Leftrightarrow\left(3y+1\right)^2-5y^2-8y=3\)
\(\Leftrightarrow\left(y-1\right)\left(2y+1\right)=0\Leftrightarrow\left[{}\begin{matrix}y=1\Leftrightarrow x=4\\y=-\dfrac{1}{2}\Leftrightarrow x=-\dfrac{1}{2}\end{matrix}\right.\)