thực hiện phép tính : (x^3)^2 : (x2)^3
Thực hiện phép tính:
1)(x+x2-6):(x+3)
2)(x+x2-30):(x+6)
3)(5-3x+6x2):(2x-1)
\(1,=\left(x+3\right)\left(x-2\right):\left(x+3\right)=x-2\\ 2,=\left(x-5\right)\left(x+6\right):\left(x+6\right)=x-5\\ 3,=\left[3x\left(2x-1\right)-5\right]:\left(2x-1\right)=3x.dư.\left(-5\right)\)
1)\(\left(x+x^2-6\right):\left(x+3\right)=\left[x\left(x+3\right)-2\left(x+3\right)\right]:\left(x+3\right)=\left[\left(x+3\right)\left(x-2\right)\right]:\left(x+3\right)=x-2\)
2) \(\left(x+x^2-30\right):\left(x+6\right)=\left[x\left(x+6\right)-5\left(x+6\right)\right]:\left(x+6\right)=\left[\left(x+6\right)\left(x-5\right)\right]:\left(x+6\right)=x-5\)
3) \(\left(5-3x+6x^2\right):\left(2x-1\right)=\left[3x\left(2x-1\right)+5\right]:\left(2x-1\right)=3x+\dfrac{5}{2x-1}\)
Thực hiện phép tính :
(x -3 )2 - x2 + 10x - 7
`@` `\text {Ans}`
`\downarrow`
`(x-3)^2 - x^2 + 10x - 7`
`= x^2 - 6x + 9 - x^2 + 10x - 7`
`= (x^2 - x^2) + (-6x + 10x) + (9-7)`
`= 4x + 2`
\(\left(x-3\right)^2-x^2+10x-7\)
\(=\left(x^2-6x+9\right)-x^2+10x-7\)
\(=\left(x^2-x^2\right)-\left(6x-10x\right)+\left(9-7\right)\)
\(=4x+2\)
\(=2\left(2x+1\right)\)
Thực hiện phép tính :
1.(2x+3).(x-5)+2x(3-x)+x-10
2.(-x-2)3+(2x-4).(x2+2x+4)-x2.(x-6)
1.(2x+3).(x-5)+2x(3-x)+x-10
=2x^2 -10x+3x-15+6x-2x^2+x-10
=2x-25
2.(-x-2)3+(2x-4).(x2+2x+4)-x2.(x-6)
=-x^3+6x^2-12x-8+2x^3+4x^2+8x-4x^2+8x-16-x^3+6x^2
V . CÁC PHÉP TOÁN VỀ PHÂN THỨC :
Bài 1 : Thực hiện các phép tính sau :
b) x+3/x-2+4+x/2-x
Bài 2 : Thức hiện các phép tính sau :
a) x+1/2x+6+2x+3/x2+3x
d) 3/2x2y +5/xy2 + x/y3
e) x/x-2y +x/x+2y + 4xy/4y2-x2
g) x+3/x+1 +2x-1/x-1 +x+5/X2-1 ;
Bài 1:
b: \(=\dfrac{x+3-4-x}{x-2}=\dfrac{-1}{x-2}\)
Bài 2:
a: \(=\dfrac{x+1}{2\left(x+3\right)}+\dfrac{2x+3}{x\left(x+3\right)}\)
\(=\dfrac{x^2+x+4x+6}{2x\left(x+3\right)}=\dfrac{x^2+5x+6}{2x\left(x+3\right)}=\dfrac{x+2}{2x}\)
d: \(=\dfrac{3}{2x^2y}+\dfrac{5}{xy^2}+\dfrac{x}{y^3}\)
\(=\dfrac{3y^2+10xy+2x^3}{2x^2y^3}\)
e: \(=\dfrac{x^2+2xy+x^2-2xy-4xy}{\left(x+2y\right)\left(x-2y\right)}=\dfrac{2x^2-4xy}{\left(x+2y\right)\cdot\left(x-2y\right)}=\dfrac{2x}{x+2y}\)
Thực hiện phép tính x+3/x - x/x-3 +9/x2-3x
\(=\dfrac{x^2-9-x^2+9}{x\left(x-3\right)}=0\)
\(\dfrac{x+3}{x}-\dfrac{x}{x-3}+\dfrac{9}{x^2-3x}=\dfrac{x^2-9-x^2+9}{x\left(x-3\right)}=\dfrac{0}{x\left(x-3\right)}=0\)
Thực hiện phép tính sau:
a)6xy.(2x2-\(\dfrac{2}{3}\)xy+\(\dfrac{1}{2}\)y2)
b)(x+3).(x2+3x-5)-x.(x-2)2
\(a,=12x^3y-4x^2y^2+3xy^3\\ b,=x^3+3x^2-5x+3x^2+9x-15-x^3-4x^2+4x\\ =2x^2+8x-15\)
b: Ta có: \(\left(x+3\right)\left(x^2+3x-5\right)-x\left(x-2\right)^2\)
\(=x^3+3x^2-5x+3x^2+9x-15-x^3+4x^2-4x\)
\(=10x^2-15\)
thực hiện phép tính:
(-2x-1). (x2+5x-3)-(x-1)3
(-2x - 1)(x2 + 5x - 3) - (x - 1)3
= -2x3 - 10x2 + 6x - x2 - 5x + 3 - x3 + 3x2 - 3x + 1
= -3x3 - 8x2 - 2x + 4
Thực hiện phép tính x 2 + 6 x + 9 x + 4 : ( x + 3 ) .
A. x + 3 x + 4
B. 1 x + 4
C. x - 3 x + 4
D. x + 3 x - 4
Thực hiện phép tính x 2 + 6 x + 9 x + 4 : ( x + 3 ) .
A. x + 3 x + 4
B. 1 x + 4
C. x - 3 x + 4
D. x + 3 x - 4