\(\dfrac{2x+1}{5}=\dfrac{3}{2x-1}\)
\(\Rightarrow\left(2x+1\right)\left(2x-1\right)=15\)
\(\Rightarrow\left(2x\right)^2-1=15\)
\(\Rightarrow4x^2=16\Rightarrow x^2=4\)
\(\Rightarrow x=\pm2\)
tìm x biết: \(\dfrac{2x-1}{3}=\dfrac{-5}{0,6}\)
Tìm x,y biết: \(\dfrac{2x+1}{5}=\dfrac{3y-2}{7}=\dfrac{2x+3y-1}{6x}\)
Cần giúp nhanh vs
Bài 1. Tìm x
a) \(\left|x+\dfrac{7}{4}\right|=\dfrac{1}{2}\)
b) \(\left|2x+1\right|-\dfrac{2}{5}=\dfrac{1}{3}\)
c) \(3x.\left(x+\dfrac{2}{3}\right)=0\)
d) \(x+\dfrac{1}{3}=\dfrac{2}{5}-\left(-\dfrac{1}{3}\right)\)
Bài 2. Tính nhanh
\(A=\dfrac{1}{100}-\dfrac{1}{100.99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-....-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
\(\dfrac{x-3}{5}=\dfrac{5-2x}{-11}\)
Tìm x?
a) \(\dfrac{2}{3}\)x + 0,25 = \(-\dfrac{5}{8}\) - \(\left(\dfrac{1}{2}-\dfrac{3}{4}x\right)\)
b) ( \(9x^2\) -1 ) . ( 2x + 3 ) = 0
c) \(\left|2x-\dfrac{1}{3}\right|-\dfrac{3}{4}=\left|-\dfrac{5}{6}\right|\)
d) \(\left(0,75-\dfrac{5}{6}x\right)^3\) = \(-\dfrac{27}{64}\)
e) \(\left(\dfrac{2}{5}x-\dfrac{1}{2}\right)^2=\dfrac{9}{16}\)
f) \(\dfrac{2x-3}{3}=\dfrac{3x+2}{7}\)
h)\(\left(\dfrac{2}{3}\right)^{2x+1}\) = \(\left(\dfrac{8}{27}\right)^3\)
i) \(2.5^{3x}+5^{3x+2}=3375\)
tìm x biết
1) \(\dfrac{2}{3}+\dfrac{1}{3}:x=\dfrac{3}{5}\)
2) \(\left(\dfrac{2x}{3}-3\right):\left(-10\right)=\dfrac{2}{5}\)
3) \(2\dfrac{2}{3}:x=2\dfrac{1}{12}:\left(-0,06\right)\)
4) \(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
5) \(-\dfrac{3}{5}.x-\dfrac{1}{2}=-\dfrac{1}{7}\)
6) \(\dfrac{1}{5}+2x=-2\dfrac{1}{4}\)
7)\(-\dfrac{1}{2}:x=\dfrac{3}{8}:\dfrac{9}{16}\)
8)\(\dfrac{2}{3}:x=2\dfrac{1}{2}:\left(-0,3\right)\)
9) \(\dfrac{x}{3}=\dfrac{-2}{1,5}\)
tìm x;y;z
a) \(\dfrac{2x+1}{5}=\dfrac{3y-2}{7}=\dfrac{2x+3y-1}{6x}\)
b) \(\dfrac{1+3y}{12}=\dfrac{1+5y}{5x}=\dfrac{1+7y}{4x}\)
c) \(\dfrac{3x}{8}=\dfrac{3y}{64}=\dfrac{3z}{216}\) và \(2x^2+2y^2-z^2\)
d) \(\dfrac{x^3}{8}=\dfrac{y^3}{64}=\dfrac{z^3}{216}\) và \(x^2+y^2+z^2=14\)
tìm x,y thỏa mãn:
\(\dfrac{2x-1}{5}=\dfrac{4y+2}{7}=\dfrac{2x+4y+1}{6x}\)
Tìm x, biết
a, \(\dfrac{3}{7}+\dfrac{4}{7}x=\dfrac{1}{3}\)
b, \(25-\left(5-x\right)=-7\)
c, \(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
d, \(2x\left(x-\dfrac{1}{7}\right)=0\)
e, \(\left|\dfrac{1}{2}x-\dfrac{3}{4}\right|-7=-3\)
