1. Thực hiện phép tínha) \(\left(3x^2y-6xy+9x\right).\left(\frac{-4}{3xy}\right)\)b) \(\left(\frac{1}{3}x+2y\right).\left(\frac{1}{9}x^2-\frac{2}{3}xy+4y^2\right)\)c) (x-2) ( \(x^2-5x+1\)) + x ( \(x^2+11\))d) (x - 3y ) \(\left(x^2+3xy+9y^2\right)\)e) \(\left(3+x\right)\left(x^2+3x-5\right)\)f) (x+2)(x-2)-(2x+1)2. Rút gọn biểu thứca ) \(\left(3x+2\right)^2+2\left(2+3x\right)\left(1-2y\right)+\left(2y-1\right)^2\)b...
Đọc tiếp
1. Thực hiện phép tính
a) \(\left(3x^2y-6xy+9x\right).\left(\frac{-4}{3xy}\right)\)
b) \(\left(\frac{1}{3}x+2y\right).\left(\frac{1}{9}x^2-\frac{2}{3}xy+4y^2\right)\)
c) (x-2) ( \(x^2-5x+1\)) + x ( \(x^2+11\))
d) (x - 3y ) \(\left(x^2+3xy+9y^2\right)\)
e) \(\left(3+x\right)\left(x^2+3x-5\right)\)
f) (x+2)(x-2)-(2x+1)
2. Rút gọn biểu thức
a ) \(\left(3x+2\right)^2+2\left(2+3x\right)\left(1-2y\right)+\left(2y-1\right)^2\)
b ) \(\left(3x+1\right)^2-2\left(3x+1\right)\left(3x+5\right)+\left(3x+5\right)^2\)
c) \(2x\left(2x-1\right)^2-3x\left(x+3\right)\left(x-3\right)-4x\left(x+1\right)^2\)
cau a : (3x^2y-6xy+9x)(-4/3xy)
=-4/3xy.3x^2y+4/3xy.6xy-4/3xy.9x
=-4x+8-8y
cau b : (1/3x+2y)(1/9x^2-2/3xy+4y^2)
=(1/3)^3-2/9x^2y+8y^3+4/3xy^2+2/9x^2y-4/3xy^2+8y^3
=(1/3)^3 + (2y)^3x-2
cau c : (x-2)(x^2-5x+1)+x(x^2+11)
=x^3-5x^2+x-2x^2+10x-2+x^3+11x
=2x^3-7x^2+22x-2
cau d := x^3 + 6xy^2 -27y^3
cau e := x^3 + 3x^2 -5x - 3x^2y - 9xy = 15y
cau f := x^2-2x+2x -4-2x-1
= x(x-2)-5
cau e la + 15y ko phai =15y