(x-3y)(x2+3x+9y2)
=(x-3y)(x2+3x+(3y)2)
=x3-(3y)3
(x-3y)(x2+3x+9y2)
=(x-3y)(x2+3x+(3y)2)
=x3-(3y)3
3x+2/x2-2x+1 - 6/x2-1 - 3x-2/x^2+2x+1
1/ Thực hiện phép tính:
a/ x2(x - 2x3)
b/(x2+1).5x
c/(x-2)(x2+2x+4)
d/ (x - 2)(x2+2x+4)
e/ (x2 - 1)(x2+ 1)
f) (2x-1)(3x + 2)(3 - x)
Bài1:Làm tính nhân:
a) 2x. (x2– 7x -3) b) ( -2x3+ y2-7xy). 4xy2 c)(-5x3).(2x2+3x-5)
d)(x2-2x+3). (x-4) e) ( 2x3-3x -1). (5x+2) g) 3(2x-1)-5(x-3)
6). – x2 y(xy2 – 1/2 xy + 3/4 x2 y2 )
7). (3xy – x2 + y). 2/3 x2 y
8). (4x3 – 5xy + 2x)( – 1/2 xy)
9). 2x2 (x2 + 3x + 1/2 )
10). – 3/2 x4 y2 (6x4 − 10/9 x2 y3 – y5 )
11). 2 3 x3 (x + x2 – 3/4 x5 )
12). 2xy2 (xy + 3x2 y – 2/3 xy3 )
13). 3x(2x3 – 1/3 x2 – 4x)
14). 3/5 x3 y5 (7x4 + 5x2 y − 10/21 x4 y3 –y4 )
Rút gọn biểu thức:
a, \(2x^2\)+3( x+1).( x-1) - 5x.(x+1)
b, (4x+3y).( 2x-5y) - ( 2x +6y).( 3x-5y)
c,( \(2x^3\)+3y).(\(2x^4y\)- \(3x^2y^2\)+ \(4y^3\))
A(x)= -x3 -x (5x3+2-3x )+2+5x4-12x-x2 tại /x/=1
2x2 (x-2)-3x ( x2-2x+3)
1/ Thực hiện phép nhân :
a) x2 ( 5x3 - x - \(\dfrac{1}{2}\))
b) ( 3xy - x2 + y ) \(\dfrac{2}{3}\)x2y
c) x2 ( 4x3 - 5xy + 2x ) ( -\(\dfrac{1}{2}\) xy )
2/ Tìm x, biết
a) 3x( 12x - 4 ) - 9x (4x - 3 ) = 30
b ) x( 5 - 2x ) + 2x ( x - 1 )= 15
Bài 1 : Chứng minh rằng : biểu thức sau không phụ thuộc vào x.
A = 2x.(x-5y) + (y -5x ) . ( -3y) -3(x^2 -y^2) -1
B = (3x -5 ) .(2x +11) -(2x+3)(3x+7)
\(\left(3x^3y-\dfrac{1}{2}x^2+\dfrac{1}{5}xy\right).6xy^3\)