1/2x2 + 4x
2/15x3 + 5x2 - 10x
3) 5x2(x-2y) + 15x (x -2y)
4) 3(x - y) + 5x(y - x)
5/ 5x2 - 10x
6) 3x-6y
7)25x2+5x3+x2y
8)14x2y-21xy2+28x2y2
9)x(y-1)- y(y-1)
10) 10x(x-y)-8y(y-x)
giúp mình vs mn cảm ơn mn rất nhiều ạ
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Lời giải:
a. $(x+y)-(x-y)=x+y-x+y=(x-x)+y+y=0+2y=2y$
b. $3x(5x^2-2x-1)-15x^3=15x^3-6x^2-3x-15x^3=-6x^2-3x$
c. $(5x-2y)(x^2-xy+1)+7x^2y=5x^3-5x^2y+5x-2x^2y+2xy^2-2y+7x^2y$
$=5x^3+(-5x^3y-2x^2y+7x^2y)+5x+2xy^2-2y$
$=5x^3+5x+2xy^2-2y$
Bài 1:
a: \(3x-6y=3\cdot x-3\cdot2y=3\left(x-2y\right)\)
b: \(14x^2y-21xy^2+28x^2y^2\)
\(=7xy\cdot2x-7xy\cdot3y+7xy\cdot4xy\)
\(=7xy\left(2x-3y+4xy\right)\)
c: \(10x\left(x-y\right)-8y\cdot\left(y-x\right)\)
\(=10x\left(x-y\right)+8y\left(x-y\right)\)
\(=\left(x-y\right)\left(10x+8y\right)\)
\(=\left(2\cdot5x+2\cdot4y\right)\left(x-y\right)\)
\(=2\left(5x+4y\right)\left(x-y\right)\)
bài 2:
a: Đề thiếu vế phải rồi bạn
b: \(x^3-13x=0\)
=>\(x\left(x^2-13\right)=0\)
=>\(\left[{}\begin{matrix}x=0\\x^2-13=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x^2=13\end{matrix}\right.\)
=>\(\left[{}\begin{matrix}x=0\\x=\pm\sqrt{13}\end{matrix}\right.\)
Bài 1:
a, $3x-6y$
$=3(x-2y)$
b, $14x^2y-21xy^2+28x^2y^2$
$=7xy(2x-3y+4xy)$
c, $10x(x-y)-8y(y-x)$
$=10x(x-y)-8y[-(x-y)]$
$=10x(x-y)+8y(x-y)$
$=(x-y)(10x+8y)$
$=2(x-y)(5x+4y)$
Bài 2:
a, Đề thiếu rồi bạn nhé.
b, \(x^3-13x=0\)
\(\Rightarrow x\left(x^2-13\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x^2-13=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x^2=13\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=0\\x=\sqrt{13}\\x=-\sqrt{13}\end{matrix}\right.\)
h) \(=3x\left(2y-3z\right)\left[x^2-5\left(2y-3z\right)\right]=3x\left(2y-3z\right)\left(x^2-10y+15z\right)\)
k) \(=\left(x+2\right)\left(3x-5\right)\)
l) \(=\left(18^2+3\right)\left(x+3\right)=327\left(x+3\right)\)
m) \(=7xy\left(2x-3y+4xy\right)\)
n) \(=2\left(x-y\right)\left(5x-4y\right)\)
a)5X2 - 2y = 8
2X + y = 5
b) 2X + y = 3
X – 2y = 4
c) 3X + 3y = 1
2X – y = -8
d) 4X + 5y = 3
X – 5y = 5
a) ( 10x3y - 5x2y2 - 25 x4y3) : ( -5xy)
Ta có : -5xy( -2x2 + xy + 5x3y2) : ( - 5xy)
Vậy , ta được thương là : -2x2 + xy + 5x3y2
b) ( 27x3 - y3) : ( 3x - y)
Ta có : ( 3x - y)( 9x2 + 3xy + y2) : ( 3x - y)
Vậy , ta được thương là : 9x2 + 3xy + y2
C,D chịu
d: \(=\left(x+1-5\right)\left(x+1+5\right)=\left(x-4\right)\left(x+6\right)\)
1, \(2x^2+4x=2x\left(x+2\right)\)
2, \(15x^3+5x^2-10x=5x\left(3x^2+x-2\right)=5x\left(x-\dfrac{2}{3}\right)\left(x+1\right)\)
3) \(5x^2\left(x-2y\right)+15x\left(x-2y\right)=\left(5x^2+15x\right)\left(x-2y\right)=5x\left(x+3\right)\left(x-2y\right)\)
4) \(3\left(x-y\right)+5x\left(y-x\right)=\left(x-y\right)\left(3-5x\right)\)
5) \(5x^2-10x=5x\left(x-2\right)\)
6) \(3x-6y=3\left(x-2y\right)\)
7) \(25x^2+5x^3+x^2y=x^2\left(25+5x+y\right)\)
8) \(14x^2y-21xy^2+28x^2y^2=7xy\left(2x-3y+4xy\right)\)
9) \(x\left(y-1\right)-y\left(y-1\right)=\left(x-1\right)\left(y-1\right)\)
10) \(10x\left(x-y\right)-8y\left(y-x\right)=\left(10x+8y\right)\left(x-y\right)=2\left(5x+4y\right)\left(x-y\right)\)
\(1,=2x\left(x+2\right)\\ 2,=5x\left(3x^2+x-2\right)\\ 3,=\left(x-2y\right)\left(5x^2+15x\right)=5x\left(x+3\right)\left(x-2y\right)\\ 4,=\left(x-y\right)\left(3-5x\right)\\ 5,=5x\left(x-2\right)\\ 6,=3\left(x-2y\right)\\ 7,=5x^2\left(5+x+y\right)\\ 8,=7xy\left(2x-3y+4xy\right)\\ 9,=\left(y-1\right)\left(x-y\right)\\ 10,=\left(x-y\right)\left(10x+8y\right)=2\left(5x+4y\right)\left(x-y\right)\)