thực hiện phép tính
1/ \(4xy\left(x^2-2xy+3y^2\right)\)
2/ \(\left(x^2-2\right)\left(2x^2+4+x^4\right)\)
Thực hiện các phép tính sau :
a) \(\left(\dfrac{5x+y}{x^2-5xy}+\dfrac{5x-y}{x^2+5xy}\right).\dfrac{x^2-25y^2}{x^2+y^2}\)
b) \(\dfrac{4xy}{y^2-x^2}:\left(\dfrac{1}{x^2+2xy+y^2}-\dfrac{1}{x^2-y^2}\right)\)
c) \(\left[\dfrac{1}{\left(2x-y\right)^2}+\dfrac{2}{4x^2-y^2}+\dfrac{1}{\left(2x+y\right)^2}\right].\dfrac{4x^2+4xy+y^2}{16x}\)
d) \(\left(\dfrac{2}{x+2}-\dfrac{4}{x^2+4x+4}\right):\left(\dfrac{2}{x^2-4}+\dfrac{1}{2-x}\right)\)
Thực hiện các phép nhân:
a) \(\left( {x - y} \right)\left( {x - 5y} \right)\)
b) \(\left( {2x + y} \right)\left( {4{x^2} - 2xy + {y^2}} \right)\)
`a, (x-y)(x-5y)`
`= x^2 - xy - 5xy + 5y^2`
`= x^2 - 6xy + 5y^2`
`b, (2x+y)(4x^2 -2xy + y^2)`
`= (2x)^3 + y^3`
`= 8x^3 + y^3`
a) \(\left(x-y\right)\left(x-5y\right)\)
\(=x^2-5xy-xy+5y^2\)
\(=x^2-6xy+5y^2\)
b) \(\left(2x+y\right)\left(4x^2-2xy+y^2\right)\)
\(=8x^3-4x^2y+2xy^2+4x^2y-2xy^2+y^3\)
\(=8x^3+y^3\)
Thực hiện phép tính:
a) \(3x.\left(2x^2-3x+4\right)\)
b) \(\left(x+3\right)^2+\left(3x-2\right)\left(x+4\right)\)
c) \(\dfrac{2x-4}{x-1}+\dfrac{2x+2}{x^2-1}\)
`a)3x(2x^2-3x+4)`
`=6x^3-9x^2+12x`
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`b)(x+3)^2+(3x-2)(x+4)`
`=x^2+6x+9+3x^2+12x-2x-8`
`=4x^2+16x+1`
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`c)[2x-4]/[x-1]+[2x+2]/[x^2-1]` `ĐK: x \ne +-1`
`=[(2x-4)(x+1)+2x+2]/[(x-1)(x+1)]`
`=[2x^2+2x-4x-4+2x+2]/[(x-1)(x+1)]`
`=[2x^2-2]/[x^2-1]`
`=2`
BT10: Thực hiện phép tính
\(a,-xyz^2\)\(-3xz.yz\)
\(b,-8x^2\)\(y-x.\left(xy\right)\)
\(c,4xy^2\) \(.x-\left(-12x^2y^2\right)\)
\(d,\dfrac{1}{2}x^2y^3-\dfrac{1}{3}x^2y.y^2\)
\(e,3xy\left(x^2y\right)-\dfrac{5}{6}x^3y^2\)
\(f,\dfrac{3}{4}x^4y-\dfrac{1}{6}xy.x^3\)
a: =-4xyz^2
b: =-9x^2y
c: =16x^2y^2
d: =1/6x^2y^3
e: =13/6x^3y^2
f: =7/12x^4y
a) -xyz² - 3xz.yz
= -xyz² - 3xyz²
= -4xyz²
b) -8x²y - x.(xy)
= -8x²y - x²y
= -9x²y
c) 4xy².x - (-12x²y²)
= 4x²y² + 12x²y²
= 16x²y²
d) 1/2 x²y³ - 1/3 x²y.y²
= 1/2 x²y³ - 1/3 x²y³
= 1/6 x²y³
e) 3xy(x²y) - 5/6 x³y²
= 3x³y² - 5/6 x³y²
= 13/6 x³y²
f) 3/4 x⁴y - 1/6 xy.x³
= 3/4 x⁴y - 1/6 x⁴y
= 7/12 x⁴y
1.rút gọn biểu thuc P=\(\dfrac{2}{x+3}+\dfrac{1}{x-3}+\dfrac{9-x}{9-x^2}\) với x\(\ne-3vàx\ne3\)
2.thực hiện phép tính \(\left(2x^4-3x^3-3x^2+6x-1\right):\left(x^2-2\right)\)
\(\left(15x^4y^6-12^3y^4-18x^2y^3\right):\left(-6x^2y^2\right)\)
thực hiện phép tính
a.\(-2xy^2.\left(x^3y-2x^2y^2+5xy^3\right)\)
b.\(\left(-2x\right).\left(x^3-3x^2-x+1\right)\)
c.3x\(^2\left(2x^3-x+5\right)\)
d.\(\left(-10x^3+\frac{2}{5}y-\frac{1}{3}z\right).\left(-\frac{1}{2}xy\right)\)
e.\(\left(3x^2y-6xy+9x\right).\left(-\frac{4}{3}xy\right)\)
f.\(\left(4xy+3y-5x\right).x^2y\)
a) Ta có: \(-2xy^2\cdot\left(x^3y-2x^2y^2+5xy^3\right)\)
\(=-2x^4y^3+4x^3y^4-10x^2y^5\)
b) Ta có: \(\left(-2x\right)\cdot\left(x^3-3x^2-x+1\right)\)
\(=-2x^4+6x^3+2x^2-2x\)
c) Ta có: \(3x^2\left(2x^3-x+5\right)\)
\(=6x^5-3x^3+15x^2\)
d) Ta có: \(\left(-10x^3+\frac{2}{5}y-\frac{1}{3}z\right)\cdot\left(-\frac{1}{2}xy\right)\)
\(=5x^4y-\frac{1}{5}xy^2+\frac{1}{6}xyz\)
e) Ta có: \(\left(3x^2y-6xy+9x\right)\cdot\left(-\frac{4}{3}xy\right)\)
\(=-4x^3y^2+8x^2y^2-12x^2y\)
f) Ta có: \(\left(4xy+3y-5x\right)\cdot x^2y\)
\(=4x^3y^2+3x^2y^2-5x^3y\)
thực hiện phép tính:
a,\(\left(9x^2y^3-15x^4y^4\right):3x^2y-\left(2-3x^2y\right)y^2\)
b,\(\left(6x^2-xy\right):x+\left(2x^3y+3xy^2\right):xy-\left(2x-1\right)x\)
c,\(\left(x^2-xy\right):x-+\left(6x^2y^5-9x^3y^4+15x^4y^2\right):\dfrac{3}{2}x^2y^3\)
Thực hiện phép tính
a, \(A=\left(3x^2y-11x^2-5y\right)\left(8xy-5x+6\right)\)
b,\(B=\left(-4x^2y-5x^2+3y^2\right)\left(2x^2-xy+3y^2\right)\)
c,\(C=5\left(2x-1\right)^2+4\left(x-1\right)\left(x+3\right)-2\left(3x-1\right)\left(3x+1\right)\)
A= 3x2 y-11x2-5y.8xy-5+6
=(3-11-5.8-5+6).(x2.x2.x).(y.y.y)
=-47x5y3
thực hiên phép tính
a.\(\dfrac{x^2+y^2}{4\left(x+y\right)}+\dfrac{2xy}{4\left(x+y\right)}\)
b.\(\dfrac{x+5}{2x-2}-\dfrac{4}{x^2-1}:\dfrac{2}{x+1}\)
a, \(\dfrac{x^2+y^2}{4\left(x+y\right)}+\dfrac{2xy}{4\left(x+y\right)}\)=\(\dfrac{x^2+2xy+y^2}{4\left(x+y\right)}\) = \(\dfrac{\left(x+y\right)^2}{4\left(x+y\right)}\) =\(\dfrac{x+y}{4}\)
a. \(\dfrac{x^2+y^2}{4\left(x+y\right)}+\dfrac{2xy}{4\left(x+y\right)}\)
\(=\dfrac{x^2+2xy+y^2}{4\left(x+y\right)}\)
\(=\dfrac{\left(x+y\right)^2}{4\left(x+y\right)}\)
\(=\dfrac{x+y}{4}\)
b. \(\dfrac{x+5}{2x-2}-\dfrac{4}{x^2-1}:\dfrac{2}{x+1}\)
\(=\dfrac{x+5}{2\left(x-1\right)}-\dfrac{4}{\left(x+1\right)\left(x-1\right)}:\dfrac{2}{x+1}\)
\(=\dfrac{x+5}{2\left(x-1\right)}-\dfrac{2}{x-1}\)
\(=\dfrac{x+5}{2\left(x-1\right)}-\dfrac{4}{2\left(x-1\right)}\)
\(=\dfrac{x+1}{2\left(x-1\right)}\)
a) Ta có: \(\dfrac{x^2+y^2}{4\left(x+y\right)}+\dfrac{2xy}{4\left(x+y\right)}\)
\(=\dfrac{x^2+2xy+y^2}{4\left(x+y\right)}\)
\(=\dfrac{\left(x+y\right)^2}{4\left(x+y\right)}\)
\(=\dfrac{x+y}{4}\)
b) Ta có: \(\dfrac{x+5}{2x-2}-\dfrac{4}{x^2-1}:\dfrac{2}{x+1}\)
\(=\dfrac{x+5}{2\left(x-1\right)}-\dfrac{4}{\left(x-1\right)\left(x+1\right)}\cdot\dfrac{x+1}{2}\)
\(=\dfrac{x+5}{2\left(x-1\right)}-\dfrac{2}{x-1}\)
\(=\dfrac{x+5}{2\left(x-1\right)}-\dfrac{4}{2\left(x-1\right)}\)
\(=\dfrac{x+5-4}{2\left(x-1\right)}\)
\(=\dfrac{x+1}{2x-2}\)