\(\text{a) }\left(x-1\right)\left(x+1\right)\left(x+2\right)\\ =\left(x^2-1\right)\left(x+2\right)\\ =x^2\left(x+2\right)-\left(x+2\right)\\ =x^3+2x^2-x-2\)
\(\text{b) }\dfrac{1}{2}x^2y^2\left(2x+y\right)\left(2-y\right)\\ =\dfrac{1}{2}x^2y^2\left(4x^2-y^2\right)=2x^4y^2-\dfrac{1}{2}x^2y^4\)
bài 1 ;thực hiện phép tính
a,(x-1).(x+1).(x+2)
b,\(\dfrac{1}{2}x^2y^2\).(2x+y).(2x-y)
bài 2;tìm x hoặc y biết ;
a,2x.(x-5)-x(2x+3)=26
b,(3y2-y+1).(y-1)+y2.(4-3y)-\(\dfrac{5}{2}\)=0
c;2x2+3(x-1).(x+1)=5x(x+1)
Thuc hien phep tinh
a, [ x2y2- 1/3xy+3y13xy+3y ] (x-3y)
b, (x^2+xy+y^2) (x-y)
c, (1/5x-1) (x^2-5x+2)
d, (x^2-2xy+y^2) (x-y)
1. làm tính nhân
a) (x - y)(x2 + xy + y2)
b) (a3 - 2a2 + a - 1)(a - 5)
c) (x2 - 2x + y2)(x - y) - 3xy (y - x)
2. tìm x:
a. (12x - 5)(x + 1) + (6x - 2)(3 - 2x ) = 5
b. (x - 5)(2x + 3 ) - 2x( x - 3 ) + x + 7 = -8
a)(2x-1)(x+5)+(x+4)(x-4)
b)x(x-y)-2xy(x-y)+2y^2-x^3
c)-(x^2)(x^2-2x+4)-x(x-1)(x+1)
Thực hiện các phép tính sau:
a).\(\left(\dfrac{2x+1}{2x-1}-\dfrac{2x-1}{2x+1}\right):\dfrac{4x}{10x-5}\)
b). \(\left(\dfrac{1}{x^2+1}-\dfrac{2-x}{x+1}\right):\left(\dfrac{1}{x}+x-2\right)\)
c). \(\dfrac{1}{x-1}-\dfrac{x^3-x}{x^2+1}.\left(\dfrac{1}{x^2-2x+1}+\dfrac{1}{1-x^2}\right)\)
d). \(\left(\dfrac{x^2+xy}{x^3+x^2y+xy^2+y^3}+\dfrac{y}{x^2+y^2}\right):\left(\dfrac{1}{x-y}-\dfrac{2xy}{x^3-x^2y+xy^2-y^3}\right)\)
Bài 1: Thực hiện các phép tính sau
a, ( x2 -1 )( x2 + 2x )
b, ( x + 3 )( x2 + 3x -5 )
c, ( x -2y )( x2y2 - xy + 2y )
d, ( 1/2xy -1 )( x3 -2x -6 )
CMR: biểu thức sau không phụ thuộc vào biến :
a)(x-y)(x^3+x^2y+xy^2+y^3)=x^4-y^4
b)(2-x)(1+2x)+(1+x)-(x^4+x^3-5x^2-5)
c)(x^2-7)(x+2)-(2x-1)(x-14)+x(x^2-2x-22)+35
Bài 1
1) (x^2-2x+3)*(x-4)
2) (2x^2-3x-1)*(5x+2)
3) (x^2-2xy+y^2)*(y^2+2xy+x^2+1)
4) (x-7)*(x+5)*(x-5)
5) (x+2y)*(x-y)
6) (x+5)*(x^2-2x+3)
7) 2x(x+5)*(x-1)
8) (x-2y)*(x+2y)
9) (x-1)*(x^2+x+1)
10) (1-2x^2+x)*(x-4+x^2)
BT lam tinh nhan
a)(x^3+2x^2y-5xy^2-3y^3)(5x-4y)
b)(x+1)(x-2)(2x-1)
c)(2x+y)(4x^2-2xy+y^2)
d)(a^3+a^2b+ab^2+b^3)(a-b)
