Cho A = \(\left(\dfrac{1}{1-x}+\dfrac{2}{x+1}-\dfrac{5-x}{1-x^2}\right):\dfrac{1-2x}{x^2-1}\)
a) Rút gọn A.
b) Tìm x để A > 0
Cho biểu thức A=\(\left(\dfrac{4}{x+2}+\dfrac{2}{x-2}+\dfrac{5x-6}{4-x^2}\right):\dfrac{1}{3x-2x^2-6}\)
a. Rút gọn A.
b. Tìm x để A=<0
c. Tìm GTLN của A khi x >2
1) giải phương trình :
a) \(\left(2+3\right)\left(\dfrac{3x+8}{2-7x}+1\right)=\left(x-5\right)\left(\dfrac{3x+8}{2-7x}+1\right)\)
b) \(\dfrac{7x+10}{x+1}\left(x^2-x-2\right)-\dfrac{7x+10}{x+1}\left(2x^2-3x-5\right)=0\)
c) \(\dfrac{2x+5}{x+3}+1=\dfrac{4}{x^2+2x-3}-\dfrac{3x-1}{1-x}\)
d) \(\dfrac{13}{2x^2+x-21}+\dfrac{1}{2x+7}+\dfrac{6}{9-x^2}=0\)
i) \(\dfrac{x-49}{50}+\dfrac{x-50}{49}=\dfrac{49}{x-50}+\dfrac{50}{x-49}\)
k) \(\dfrac{1+\dfrac{x}{x+3}}{1-\dfrac{x}{x+3}}=3\)
I : Giải các phường trình sau
a) \(\left(3x-2\right)\left(\dfrac{2\left(x+3\right)}{7}-\dfrac{4x-3}{5}\right)=0\)
b) \(\left(x-\dfrac{3}{4}\right)^2+\left(x-\dfrac{3}{4}\right)\left(x-\dfrac{1}{2}\right)=0\)
c) \(\dfrac{12}{9-x^2}+\dfrac{2}{x-3}+\dfrac{3}{x+3}=1\)
d) \(\dfrac{1}{x-1}+\dfrac{2}{x^2+x+1}=\dfrac{3x^2}{x^3-1}\)
help me
1. \(\dfrac{5\left(x-1\right)+2}{6}-\dfrac{7x-1}{4}=\dfrac{2\left(2x+1\right)}{7}-5\)
2. \(x-\dfrac{3\left(x+30\right)}{15}-24\dfrac{1}{2}=\dfrac{7x}{10}-\dfrac{2\left(10x+2\right)}{5}\)
3. \(14\dfrac{1}{2}-\dfrac{2\left(x+3\right)}{5}=\dfrac{3x}{2}-\dfrac{2\left(x-7\right)}{3}\)
4. \(\dfrac{x+1}{3}+\dfrac{3\left(2x+1\right)}{4}=\dfrac{2x+3\left(x+1\right)}{6}+\dfrac{7+12x}{12}\)
5. \(\dfrac{3\left(2x-1\right)}{4}-\dfrac{3x+1}{10}+1=\dfrac{2\left(3x+2\right)}{5}\)
6. \(x-\dfrac{3}{17}\left(2x-1\right)=\dfrac{7}{34}\left(1-2x\right)+\dfrac{10x-3}{2}\)
7. \(\dfrac{3\left(x-3\right)}{4}+\dfrac{4x-10,5}{10}=\dfrac{3\left(x+1\right)}{5}+6\)
8. \(\dfrac{2\left(3x+1\right)+1}{4}-5=\dfrac{2\left(3x-1\right)}{5}-\dfrac{3x+2}{10}\)
1) giải pt :
a) \(\dfrac{x-5}{100}+\dfrac{x-4}{101}+\dfrac{x-3}{102}=\dfrac{x-100}{5}+\dfrac{x-101}{4}+\dfrac{x-102}{3}\)
b) \(\dfrac{29-x}{21}+\dfrac{27-x}{23}+\dfrac{25-x}{25}+\dfrac{23-x}{27}+\dfrac{21-x}{29}=-5\)
2) giải pt :
a) \(\left(5x+1\right)^2=\left(3x-2\right)^2\)
b) \(\left(x+2\right)^3=\left(2x+1\right)^3\)
c) \(\left(x+3\right)^4+\left(x+5\right)^4=2\)
d) \(x^4-3x^3+4x^2-3x+1=0\)
a) \(8\left(x+\dfrac{1}{x}\right)^2+4\left(x^2+\dfrac{1}{x^2}\right)^2-4\left(x^2+\dfrac{1}{x^2}\right)\left(x+\dfrac{1}{x}\right)^2=\left(x+4\right)^2\)
b) \(\left(6x+7\right)^2\left(3x+4\right)\left(x+1\right)=6\)
c) \(\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)=840\)
cho M= \(\dfrac{x^2}{\left(x+y\right)\left(1-y\right)}\)-\(\dfrac{y^2}{\left(x+y\right)\left(1+x\right)}\)-\(\dfrac{X^2y^2}{\left(1+x\right)\left(1-y\right)}\)
a, rút gọn M
b, tìm các cặp số nguyên x,y để biểu thức có giá trị là -2010