Tìm x biết :
a) \(\frac{x}{6}\) = \(\frac{8}{3}\) b) \(\frac{3}{x-1}\) = \(\frac{21}{6}\)
c) \(\frac{x-1}{x-5}\) = \(\frac{6}{7}\) d) \(\frac{2x+3}{6}\) = \(\frac{7x-3}{15}\)
e) \(\frac{x+1}{x-2}\) = \(\frac{3}{4}\) g) \(\frac{12-7x}{-13}\) = \(\frac{4-3x}{-5}\)
Các bn ơi giúp mình với mình cảm ơn trước nha
a) \(\frac{x}{6}=\frac{8}{3}\Rightarrow x=\frac{6\cdot8}{3}=16\)
b)\(\frac{3}{x-1}=\frac{21}{6}\)
\(\Rightarrow21\left(x-1\right)=3\cdot6\)
\(\Rightarrow21x-21=18\)
\(\Rightarrow21x=39\)
\(\Rightarrow x=\frac{13}{7}\)
c)\(\frac{x-1}{x-5}=\frac{6}{7}\)
\(\Rightarrow7\left(x-1\right)=6\left(x-5\right)\)
\(\Rightarrow7x-7=6x-30\)
\(\Rightarrow7x-6x=-30+7\)
\(\Rightarrow x=-23\)
d)\(\frac{2x+3}{6}=\frac{7x-3}{15}\)
\(\Rightarrow15\left(2x+3\right)=6\left(7x-3\right)\)
\(\Rightarrow30x+45=42x-18\)
\(\Rightarrow30x-42x=-18-45\)
\(\Rightarrow-12x=-63\)
\(\Rightarrow x=\frac{21}{4}\)
e)\(\frac{x+1}{x-2}=\frac{3}{4}\)
\(\Rightarrow4\left(x+1\right)=3\left(x-2\right)\)
\(\Rightarrow4x+4=3x-6\)
\(\Rightarrow4x-3x=-6-4\)
\(\Rightarrow x=-10\)
g)\(\frac{12-7x}{-13}=\frac{4-3x}{-5}\)
\(\Rightarrow-5\left(12-7x\right)=-13\left(4-3x\right)\)
\(\Rightarrow-60x+35=-52+39x\)
\(\Rightarrow-99x=-87\)
\(\Rightarrow x=\frac{29}{33}\)
a) x = 4
b) x = 13/7
c) x = -23
d) x = 21/4
e) x = -10
g) x = -8/39
hôm nay cô giáo giao nhìu bt quá mink k bk làm các bạn cố gắng giúp mink nhé///// mik cảm ơn nhìu !!@@
