tim xy |x+1/3|+|x+1+!/3|=4+1/2x
a,tim x biet |x-2|+|3-2x|=2x+1
b,tim x,y thuoc Z biet xy+2x-y=5
c, tinh A=(1-1/15)(1-1/21)(1-1/28).....(1-1/210)
Tim so nguyen x,y biet
(x+1)^2+(y-1)^2=0
(x+3)×(y+1)=3
xy-2x=5
(x+3).(y+1)=3
--->x+3,y+1 thuộc Ư(3)={1,3,-1,-3}
Ta có bảng sau
x+3 1 -1
y+1 3 -3
y 2 -4
x -2 -4
--->(x,y) thuộc(-2,2),(-4,-4)
Tim x,y biet
a)(2x +1)(3y-2)=55
b)(x+1)(xy-1)=3
Tim X,y thuộc Z
(X-3).(2x+1)=7
(2x+1).(3x-2)=-55
Xy+3x-7y=21
tim x biet x-y=xy-1
cm x^3 -x^2 -2x^2 +2x chia het cho 6
Tim cac cap so nguyen x,y biet
a,xy=-5
b,(x+2)(2y-3)=8
c,(x-2)^2+(2x-y)^4=0
d,|x|+|y|=1
e,|2x+1|+|y|=4
f,|x-13|+|2y-8|<hoac= 0
g,|x-5|+|y+2|=2
h,|x+3|+|2y+1|=3
1)Tim MAX cua A= (6x^2-2x+1)/ x^2
2)tim MIN va MAX C= (3-4x)/(X^2+1)
3) Tim MIN va MAX P = x^2+y^2
biet giua x va y co moi quan he nhu sau : 5x^2+8xy+5y^2=36
4)tim MAX Q = -x^2-y^2+xy+2x+2y
1.Tính \(\dfrac{x}{x+2}-\dfrac{x}{x-2}\)
2.Phân tích đa thức thành nhân tử
1)\(\left(x^2y^2-8\right)-1\)
2)\(x^3y-2x^2y+xy-xy^3\)
3)\(x^3-2x^2y+xy^2\)
4)\(x^2+2x-y^2+1\)
5)\(x^2+2x-4y^2+1\)
6)\(x^2-6x-y^2+9\)
bài 1: ĐKXĐ: \(x\notin\left\{2;-2\right\}\)
\(\dfrac{x}{x+2}-\dfrac{x}{x-2}\)
\(=\dfrac{x\left(x-2\right)-x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}\)
\(=\dfrac{x^2-2x-x^2-2x}{\left(x-2\right)\left(x+2\right)}=-\dfrac{4x}{x^2-4}\)
Bài 2:
1: \(x^2y^2-8-1\)
\(=x^2y^2-9\)
\(=\left(xy-3\right)\left(xy+3\right)\)
2: \(x^3y-2x^2y+xy-xy^3\)
\(=xy\cdot x^2-xy\cdot2x+xy\cdot1-xy\cdot y^2\)
\(=xy\left(x^2-2x+1-y^2\right)\)
\(=xy\left[\left(x-1\right)^2-y^2\right]\)
\(=xy\left(x-1-y\right)\left(x-1+y\right)\)
3: \(x^3-2x^2y+xy^2\)
\(=x\cdot x^2-x\cdot2xy+x\cdot y^2\)
\(=x\left(x^2-2xy+y^2\right)=x\left(x-y\right)^2\)
4: \(x^2+2x-y^2+1\)
\(=\left(x^2+2x+1\right)-y^2\)
\(=\left(x+1\right)^2-y^2\)
\(=\left(x+1+y\right)\left(x+1-y\right)\)
5: \(x^2+2x-4y^2+1\)
\(=\left(x^2+2x+1\right)-4y^2\)
\(=\left(x+1\right)^2-4y^2\)
\(=\left(x+1-2y\right)\left(x+1+2y\right)\)
6: \(x^2-6x-y^2+9\)
\(=\left(x^2-6x+9\right)-y^2\)
\(=\left(x-3\right)^2-y^2=\left(x-3-y\right)\left(x-3+y\right)\)
tim xy
a) (2x+1).(y-3)=10
b) x-3=y. (x+2)
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