a) Giải \(\left\{{}\begin{matrix}\dfrac{2}{x+3}-\dfrac{5}{y-2}=1\\\dfrac{x+4}{x+3}+\dfrac{y+3}{y-2}=4\end{matrix}\right.\)
b) Giải : \(x^2+2\sqrt{3}x-6=0\)
Giải phương trình?:
a) A=\(\dfrac{x+1}{x^2+x+1}-\dfrac{x-1}{x^2-x+1}=\dfrac{3}{x\left(x^4+x^2+1\right)}\)
b) B=\(\dfrac{1}{x^2+9x+20}+\dfrac{1}{x^2+11x+30}+\dfrac{1}{x^2+13x+42}=\dfrac{1}{18}\)
Giải hệ phương trình : \(\left\{{}\begin{matrix}\dfrac{y}{x+\dfrac{5}{3}}\\\dfrac{y}{\left(x-1\right)+\dfrac{4}{15}}\end{matrix}\right.\)
a.\(\dfrac{x+6}{5}-\dfrac{x-2}{3}< 2\)
b. \(\dfrac{x+5}{4}-\dfrac{x^{2^{ }}-3}{6}\ge1-\dfrac{2x^{2^{ }}-1}{12}\)
c. \(x^{2^{ }}-4x+3>0\)
d. \(x^{3^{ }}-2x^{2^{ }}+3x-2\ge0\)
e. \(\left|x+1\right|+\left|x-2\right|=4\)
f. \(\dfrac{5x-1}{10}+\dfrac{2x+3}{6}>\dfrac{x-8}{15}-\dfrac{x-1}{30}\)
h.\(\dfrac{10x+3}{12}< \dfrac{15-8x}{9}\)
Giải hệ phương trình : \(\left\{{}\begin{matrix}\dfrac{y}{x+\dfrac{5}{3}}\\\dfrac{y}{x+\dfrac{4}{15}}\end{matrix}\right.\)
giải pt
\(\dfrac{1}{x^2-2x+2}+\dfrac{2}{x^2-2x+3}=\dfrac{6}{x^2-2x+4}\)
Giải:
\(\)a) \(2+\dfrac{3-2x}{5}\ge\dfrac{x+3}{4}-x\)
b) \(\left|x-2\right|+3\left|1+x\right|=2\left(x-4\right)-x\)
1) Tìm x
4x(x-1)-x(4x-2) = 5(x-3)
2. Tính hợp lý
A = \(2\dfrac{1}{315}-\dfrac{1}{651}-\dfrac{1}{105}.3\dfrac{650}{651}-\dfrac{4}{315-651} +\dfrac{4}{105}\)
\(A=\left(\dfrac{x-5\sqrt{x}}{x-25}-1\right):\left(\dfrac{25-x}{x+2\sqrt{x}-15}-\dfrac{\sqrt{x}+3}{\sqrt{x}+5}+\dfrac{\sqrt{x}-5}{\sqrt{x}+3}\right)\)
\(B=\left(\dfrac{2+x}{2-x}-\dfrac{4x^2}{x^2-4}-\dfrac{2-x}{x+2}\right):\dfrac{x^2-3x}{2x^2-x^3}\)
a) Rút gọn A & B
b) Tìm x để B > 0
c) Tính B khi \(\left|1-x\right|=0\)