a) 2xy+x2y2+1
=(xy+1)2
b) 9x2+4y2-12xy
=32x2+22y2-12xy
=(3x-2y)2
\(a,2xy+x^2y^2+1\)
\(=x^2y^2+2xy+1\)
\(=\left(xy+1\right)^2\)
\(b,9x^2+4y^2-12xy\)
\(=\left(3x\right)^2-12xy+\left(2y\right)^2\)
\(=\left(3x-2y\right)^2\)
a) 2xy+x2y2+1
=(xy+1)2
b) 9x2+4y2-12xy
=32x2+22y2-12xy
=(3x-2y)2
\(a,2xy+x^2y^2+1\)
\(=x^2y^2+2xy+1\)
\(=\left(xy+1\right)^2\)
\(b,9x^2+4y^2-12xy\)
\(=\left(3x\right)^2-12xy+\left(2y\right)^2\)
\(=\left(3x-2y\right)^2\)
bai1: rut gon cac bieu thuc sau
a, (2x-y).(4x^2+2xy+y^2)-(2x+y).(4x^2-2xy+y^2)
b, (3x+2y).(9x^2-6xy+4y^2)-27x^3
c,8x.(x-2y).(x+2y)+(y-2x).(x^2+2xy+4x^2)
bai2 :cmr
a, a^3+b^3=(a+b)^3-3ab.(a+b)
b.a^3-b^3=(a-b)+3ab,(a-b)
Rút gọn: \(\frac{2x^2-4xy}{x^2+4xy+4y^2}:\frac{4y^2-x^2}{x^2-4xy+4y^2}:\frac{5x^2y-10xy^2}{x^3+6x^2y+12xy^2+8y^3}\)
Tìm min : a) \(M=x^2-2xy+2y^2-4y+2016\)
b) \(N=x^2-2xy+2x+2y^2-4y+2016\)
bai 1: thuc hiem phep tinh.
a,(3x^3y-1/2x^2+1/5xy).6xy^3
b, 2/3x^2y.(3xy-x^2+y)
c, (xy-1).(xy+5)
d, (x^2y^2-1/2xy+2xy)x-2y
1,Thực hiện phép tính
a,-1/3xz(-9xy+15yz)+3x2(2yz2-yz)
b,(x-2)(x2-5x+1)-x(x2+11)
c,(x3+5x2-2x+1)(x-7)
d(2x2-3xy+y2)(x+y)
e,[(x2-2xy+2y2)(x+2y)-(x2+4y2)(x-y)]2xy
2,tìm x
a,6x(5x+3)+3x(1-10x)=7
b,(3x-3)95-21x)+(7x+4)(9x-5)=44
c,(x+1)(x+2)(x+5)-x2(x+8)=27
Tìm Max:
a) A=-x2 +2xy -4y2 +2x + 10y +5
b) B=-x2 -2y2 -2xy +2x -2y -15
a, x^2-y^2-2y-1
b, 5x-10y-x^2+4y^2
c, x^2-4x+3
d, x^3-9x^2y + 9xy^2-3xy^2
e, x^4 +64
bai 1: thuc hiem phep tinh
.a,(3x^3y-1/2x^2+1/5xy).6xy^3
b, 2/3x^2y.(3xy-x^2+y)
c, (xy-1).(xy+5)
d, (x^2y^2-1/2xy+2xy)x-2y
+) cho x - y = 7 tính gtbt sau
A = x(x+2) +y(y-2)-2xy +37
+) cho x+2y=5 tính gtbt sau
B = x2 + 4y2 - 2x +10 +4xy -4y