a.\(\frac{-2}{7}\)=\(\frac{4}{x}\)<=> -2.x= 4.7 <=> -2x= 28 <=> x=28:(-2)=-14
b.\(\frac{x}{20}\)=\(\frac{5}{x}\) <=> x.x=5.20 <=> \(x^2\)=100 <=> \(\left[\begin{array}{nghiempt}x^2=10^2\\x^2=\left(-10\right)^2\end{array}\right.\)<=> \(\left[\begin{array}{nghiempt}x=10\\x=-10\end{array}\right.\)
Vậy x=10 hoặc x=-10
c./x/=/-5/ <=> /x/=5 <=> x=5 hoặc x=-5
tìm x biết :
a) \(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2x\right)=0\)
b) \(\left(x.6\frac{2}{7}+\frac{3}{7}\right).2\frac{1}{5}-\frac{3}{7}=-2\)
c) \(x.3\frac{1}{4}+\left(-\frac{7}{6}\right).x-1\frac{2}{3}=\frac{5}{12}\)
d) \(5\frac{8}{17}:x+\left(-\frac{4}{17}\right):x+3\frac{1}{7}:17\frac{1}{3}=\frac{4}{11}\)
e) \(\frac{17}{2}-\left|2x-\frac{3}{4}\right|=-\frac{7}{4}\)
Tìm x biết
a) x + \(2\frac{3}{4}=5\frac{2}{3}\)
b)X x \(3\frac{1}{2}=4\frac{3}{4}\)
c) x - \(4\frac{1}{5}=3\frac{2}{7}\)
d) x - \(\frac{3}{4}=6\text{x}\frac{3}{8}\)
e) \(\frac{7}{8}:x=3\frac{1}{2}\)
\(\frac{1}{2}\)x +\(\frac{3}{5}\)x= \(\frac{-2}{5}\).
Tìm x.(giải giúp mình nhé!)
tìm x biết :
a) \(\frac{6}{7}.x=\frac{18}{23}\)
b) \(2\frac{1}{2}.x=\frac{5}{6}\)
c) \(x:2\frac{3}{4}=9\frac{5}{8}\)
d)\(7\frac{1}{7}.\frac{1}{7}.x=22\frac{1}{8}\)
tim x
\(a,\left|\frac{4}{7}-x\right|+\frac{2}{5}=0\)
\(b,6-\left|\frac{1}{4}x+\frac{2}{5}\right|=0\)
\(c,\left|x-\frac{1}{3}\right|+\left|2-\frac{4}{5}\right|=0\)
Tìm x biết:
a) \(\frac{-3}{2}.\left(7-\frac{1}{6}\right)+4.\left(x-\frac{1}{2}\right)=3\)
b)\(3.\left(x-\frac{1}{5}\right)-7.\left(\frac{5}{14}-3\right)=20\)
Bạn nào làm ơn giúp mình có cách làm cho 4 tick
Tính nhanh :
\(\frac{1}{1}x\frac{1}{2}+\frac{1}{2}x\frac{1}{3}+\frac{1}{3}x\frac{1}{4}+\frac{1}{4}x\frac{1}{5}+\frac{1}{5}x\frac{1}{6}\)
Giúp mình với nha <3 Chiều mai mình đi học rồi 
Tính nhanh
a) \(\frac{6}{7}:\left(\frac{1}{2}\text{X}\frac{3}{4}\right)-\frac{5}{8}\)
b) 34-2:\(\left(\frac{3}{5}-\frac{1}{2}\right)\)
c) \(\left(4\frac{1}{2}+\frac{1}{2}:5\frac{1}{2}\right)\text{X}\left(3\frac{5}{6}+2\frac{1}{6}\text{x}6\right)\)
tìm số x , biết :
a) \(\frac{2}{3}x-\frac{3}{2}x=\frac{5}{12}\)
b) \(\frac{2}{5}+\frac{3}{5}.\left(3x-3,7\right)=\frac{-53}{10}\)
c) \(\frac{7}{9}:\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\)
d) \(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\)
e) \(\left|x\right|-\frac{3}{4}=\frac{5}{3}\)
f) \(\left|2x-\frac{1}{3}\right|+\frac{5}{6}=1\)
