x/3=11/21
7x/21=11/21
7x=11
x= 11/7
\(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{1}{-7}\)
\(\dfrac{x}{3}=\dfrac{11}{21}\)
\(\dfrac{7x}{21}=\dfrac{11}{21}\)
=>7x=11
x=11:7
\(x=\dfrac{11}{7}\)
Tìm \(x\), biết :
a) \(x=\dfrac{1}{4}+\dfrac{2}{13}\)
b) \(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}\)
2 tìm x
a) x+25=40
b) 198-(x+4)=120
c) (2x-7).3=125
d) x +16⋮x+1
tìm x, biết:
e) \(\dfrac{2}{7-x}\)=\(\dfrac{18}{45}\) f)\(\dfrac{2x+3}{3}\)=\(\dfrac{50}{15}\) g)\(2\dfrac{x}{7}\)=\(\dfrac{75}{35}\) h)\(2\dfrac{3}{x}\)=\(\dfrac{13}{x}\)(x khác 0)
Bài 1 : Tìm x
a, x/3 = 2/3 + -3/7
b, x/7 = -3/4 + 2/-9
Mn giúp mk với !
f) \(\dfrac{x+1}{x-3}=\dfrac{x+7}{x-2}\)
Tìm \(x\) biết :
a) \(x=\dfrac{-1}{2}+\dfrac{3}{4}\)
b) \(\dfrac{x}{5}=\dfrac{5}{6}+\dfrac{-19}{30}\)
bài 45: Tìm x, biết:
a) x=\(\dfrac{-1}{2}+\dfrac{3}{4}\); b) \(\dfrac{x}{5}=\dfrac{5}{6}+\dfrac{-19}{30}\)
\(\dfrac{x}{2}\)-(\(\dfrac{3x}{5}\)-\(\dfrac{13}{5}\))=-(\(\dfrac{7}{5}\)+\(\dfrac{7}{10}\).\(x\))
\(\dfrac{2x-3}{3}\)+\(\dfrac{-3}{2}\)=\(\dfrac{5-3x}{6}\)-\(\dfrac{1}{3}\)
\(\dfrac{2}{3x}\)-\(\dfrac{3}{12}\)=\(\dfrac{4}{5}-\left(\dfrac{7}{x}-2\right)\)
tìm x biết \(\dfrac{-15}{41}+\dfrac{-138}{41}\le x\le\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{6}\)