a, \(\frac{x-2}{5}\)=\(\frac{3}{4}\)
\(\Leftrightarrow\)(x-2).4=3.5
\(\Leftrightarrow\)(x-2).4=15
\(\Leftrightarrow\)x-2=15:4
\(\Leftrightarrow\)x-2=\(\frac{15}{4}\)
\(\Leftrightarrow\)x=\(\frac{15}{4}\)+2
\(\Leftrightarrow\)x=\(\frac{23}{4}\)
Vậy ...
b,\(\frac{3}{x-1}\)=\(\frac{4}{3}\)
\(\Leftrightarrow\)3.3=(x-1).4
\(\Leftrightarrow\)9=(x-1).4
\(\Leftrightarrow\)x-1=9:4
\(\Leftrightarrow\)x-1=\(\frac{9}{4}\)
\(\Leftrightarrow\)x=\(\frac{13}{4}\)
vậy...
c,\(\frac{6}{7}\)=\(\frac{x-3}{4}\)
\(\Leftrightarrow\)6.4=7.(x-3)
\(\Leftrightarrow\)24=7.(x-3)
\(\Leftrightarrow\)x-3=\(\frac{24}{7}\)
\(\Leftrightarrow\)x=\(\frac{45}{7}\)
d,\(\frac{x-2}{4}\)=\(\frac{3-x}{2}\)
\(\Leftrightarrow\)(x-2).2=4.(3-x)
\(\Leftrightarrow\)2x-4=12-4x
\(\Leftrightarrow\)2x-4-12+4x=0
\(\Leftrightarrow\)6x-16=0
\(\Leftrightarrow\)6x=16
\(\Leftrightarrow\)x=\(\frac{8}{3}\)
