Tìm x,y thuộc Z
a,4x-xy+2y=10
b,3y-xy-x=-2
tìm x y thuộc z
a) x+y=xy
b) 2x-xy-2y=3
c) 4x-xy+5y=17
d) 2xy+2n-y=5
a: =>x-xy+y=0
=>x(1-y)+1-y-1=0
=>(x+1)(1-y)=1
=>(x+1)(y-1)=-1
=>\(\left(x+1;y-1\right)\in\left\{\left(-1;1\right);\left(1;-1\right)\right\}\)
=>\(\left(x,y\right)\in\left\{\left(-2;2\right);\left(0;0\right)\right\}\)
b: 2x-xy-2y=3
=>x(2-y)-2y+4=7
=>x(2-y)+2(2-y)=7
=>(x+2)(y-2)=-7
=>\(\left(x+2;y-2\right)\in\left\{\left(1;-7\right);\left(-7;1\right);\left(-1;7\right);\left(7;-1\right)\right\}\)
=>\(\left(x;y\right)\in\left\{\left(-1;-5\right);\left(-9;3\right);\left(-3;9\right);\left(5;1\right)\right\}\)
c: =>x(4-y)+5y-20=-3
=>x(4-y)-5(4-y)=-3
=>(4-y)(x-5)=-3
=>(x-5)(y-4)=3
=>\(\left(x-5;y-4\right)\in\left\{\left(1;3\right);\left(3;1\right);\left(-1;-3\right);\left(-3;-1\right)\right\}\)
=>\(\left(x,y\right)\in\left\{\left(6;9\right);\left(8;5\right);\left(4;1\right);\left(2;3\right)\right\}\)
Tìm x,y thuộc Z
a)49-y^2=6(x-2021)^2
b)x^2 + xy + y^2=2x+y
c)x^2 + xy + y^2=x+y
d)x^2 + 3xy + 3y^2 =3y
e)x^2 - 2xy - 5y^2=y+1
Tìm x,y thuộc Z
a)49-y^2=6(x-2021)^2
b)x^2 + xy + y^2=2x+y
c)x^2 + xy + y^2=x+y
d)x^2 + 3xy + 3y^2 =3y
e)x^2 - 2xy - 5y^2=y+1
Tìm x,y thuộc Z
a)49-y^2=6(x-2021)^2
b)x^2 + xy + y^2=2x+y
c)x^2 + xy + y^2=x+y
d)x^2 + 3xy + 3y^2 =3y
e)x^2 - 2xy - 5y^2=y+1
Tìm x,y thuộc Z
a)49-y^2=6(x-2021)^2
b)x^2 + xy + y^2=2x+y
c)x^2 + xy + y^2=x+y
d)x^2 + 3xy + 3y^2 =3y
e)x^2 - 2xy - 5y^2=y+1
Tìm x,y thuộc Z
a)49-y^2=6(x-2021)^2
b)x^2 + xy + y^2=2x+y
c)x^2 + xy + y^2=x+y
d)x^2 + 3xy + 3y^2 =3y
e)x^2 - 2xy - 5y^2=y+1
Tìm x,y thuộc Z
a)49-y^2=6(x-2021)^2
b)x^2 + xy + y^2=2x+y
c)x^2 + xy + y^2=x+y
d)x^2 + 3xy + 3y^2 =3y
e)x^2 - 2xy - 5y^2=y+1
Tìm số nguyên x biết
a,3x+3y-2xy=7
b,xy+2x+y+11=0
c,xy+x-y=4
d,2x.(3y-2)+(3y-2)=12
e,3x+4y-xy=15
f,xy+3x-2y=11
g,xy+12=x+y
h,xy-2x-y=-6
i,xy+4x=25+5y
ii,2xy-6y+x=9
iii,xy-x+2y=3
k,2.x^2.y-x^2-2y-2=0
l,x^2.y-x+xy=6
Câu: Đẳng thức nào sau đây là đúng. *
4x^3y^2 – 8x^2y^3 = 4x^2.y(xy – 2y^2)
4x^3y^2 – 8x^2y^3 = 4x^2y^2(x – 2y)
4x^3y^2 – 8x^2y^3 = x^2y^2(x – 2y)
4x^3y^2 – 8x^2y^3 = 4x^2y^2(x – y)
ta có 4 x 3 y 2 – 8 x 2 y 3 = 4 x 2 y 2 . x – 4 x 2 y 2 . 2 y = 4 x 2 y 2 ( x – 2 y )
Vậy 4x3y2 – 8x2y3 = 4x2y2(x – 2y)
Đáp án cần chọn là: C
bấm đúng cho mik đi