\(\dfrac{1}{x+1}:\dfrac{x+2}{x+1}:\dfrac{x+3}{x+2}:...:\dfrac{x+10}{x+9}\)
\(=\dfrac{1}{x+1}\cdot\dfrac{x+1}{x+2}\cdot\dfrac{x+2}{x+3}\cdot...\cdot\dfrac{x+9}{x+10}\)
\(=\dfrac{\left(x+1\right)\left(x+2\right)\cdot...\cdot\left(x+9\right)}{\left(x+1\right)\left(x+2\right)\left(x+3\right)\cdot...\cdot\left(x+9\right)\left(x+10\right)}\)
\(=\dfrac{1}{x+10}\)
Tính (rút gọn )
(x-10)^2-2(x-10)(5x-3)+(5x+3)
(x-2)^3-x(x-3)^2
(x-2)(x^2+2x+4)-x(x+1)(x-1)
(x+3)(x^2-3x+9)-x(x^2-1)
tính S=1/x(x+1)(x+2)+1/(x+1)(x+2)(x+3)+...+1/(x+8)(x+9)(x+10)
giải phương trình:
a/x-1/x^2-x+1 - x+/x^2+x+1 = 10/x(x^4+x^2+1)
b/ x+9/10 + x+10/9 = 9/x+10 + 10/x+9
c/ x^2-2x+2/x-1 + x^2-8x+20 = x^2-4x+6/x-2 + x^2-6x +12/x-3
Bài 4:Tìm x, biết:
1/ (x-1)(x^2+x+1)-x^3-6x=11
2/ 16x^2-(3x-4)^2=0
3/ x^3-x^2+3-3x=0
4/ x-1/x+2=x+2/x+1
5/1/x+2/x+1=0
6/ 9-x^2/x : (x-3)=1
\(\frac{1}{x-1}-\frac{3x^2}{x^3-1}=\frac{2x}{x^2+x+1}\)
\(\frac{x+2}{x+1}-\frac{1}{x-2}=1-\frac{3}{x^2-x-2}\)
\(\frac{1}{x}+2=\left(\frac{1}{x}+2\right)\left(x^2+1\right)\)
\(\left(x+1+\frac{1}{x}\right)^2=\left(x-1-\frac{1}{x}\right)^2\)
\(\frac{x+9}{10}+\frac{x+10}{9}=\frac{9}{x+10}+\frac{10}{x+9}\)
Thực hiện phép tính:
a. ( x-2)^3- x(x+1)(x-1)+ 6x(x-3)
b.(x-2)(x^2-2x+4)(x+2)(x^2+2x+4)
Tìm x biết:
a.(x-3)(x^2+ 3x+9)+ x(x+2)(2-x)=1
b. (x+1)^3- (x-1)^3 - 6(x-1)^2=-10
1.giải các phương trình sau:
a, 3(2x+1)/4 - 5x+3/6 = 2x-1/3 - 3-x/4
b, 19/4 - 2(3x-5)/5 = 3-2x/10 - 3x-1/4
c, x-2*3/2+3 + x-3*5/3+5 + x-5*2/5+2 = 10
d, x-3/5*7 + x-5/3*7 + x-7/3*5 = 2(1/3 + 1/5 + 1/7)
2. giải các phương trình:
a, x-1/9 + x-2/8 = x-3/7 + x-4/6
b, (1/1*2 + 1/2*3 + 1/3*4 + ... + 1/9*10) (x-1) + 1/10x = x- 9/10
1/(x(x + 1)) + 1/((x + 1)(x + 2)) + 1/((x + 2)(x - 3)) +***+ 1 (x+9)(x+10) = 5/12
1. Thực hiện phép tính:
a, 5/2x^2+6x - 4-3x^2/x^2-9
b, 5/x+1 - 10/x-(x^2+1) - 15/x^3+1
c, x+3/x+1 - 2x-1/x-1 - x-3/x^2-1
d, 1/(a-b)(a-c) + 1/(b-a)(b-c) + 1/(c-a)(c-b)
