\(\frac{x-3}{x+5}=\frac{5}{7}\)
\(\Leftrightarrow7\left(x-3\right)=5\left(x+5\right)\)
\(\Leftrightarrow7x-21=5x+25\)
\(\Leftrightarrow7x-5x=25+21\)
\(\Leftrightarrow2x=46\)
\(\Leftrightarrow x=23\)
Vậy ..........
a) \(\frac{-1}{3}-\frac{-3}{5}-\frac{1}{6}+\frac{1}{43}-\frac{-3}{7}+\frac{-1}{2}-\frac{1}{35}\)
b) \(5^x+5^{x+2}=650\)
c) \(\frac{1+3y}{12}=\frac{1+5y}{5x}=\frac{1+7y}{4x}\left(x\ne0\right)\)
\(\frac{1+3y}{12}=\frac{1+5y}{5x}=\frac{1+7y}{4x}\) tim x;y
tim x,y biet: \(\frac{1+3y}{12}=\frac{1+5y}{5x}=\frac{1+7y}{4x}\)
Tìm x biết:
a) \(\left(x-3\right)^{x+5}-\left(x-3\right)^{x+15}=0\)
b)\(\frac{1+3y}{12}=\frac{1+5y}{5x}=\frac{1+7y}{4x}\)
Tìm x;y :\(\frac{1+3y}{12}=\frac{1+5y}{5x}=\frac{1+7y}{4x}\)
tim cap so x;y
a, \(\frac{x}{3}\)=\(\frac{y}{7}\)
va xy=84
b,\(\frac{1+3y}{12}\)=\(\frac{1+5y}{5x}=\frac{1+7y}{4x}\)
Tìm x,y
\(\frac{1+3y}{12}=\frac{1+5y}{5x}=\frac{1+7y}{4x}\)
tìm x, y
\(\frac{1+3y}{12}+\frac{1+5y}{5x}+\frac{1+7y}{4x}\)
Tim cap so (x;y) biet \(\frac{1+3y}{12}\)=\(\frac{1 +5y}{5x}\)=\(\frac{1+7y}{4x}\)
