x + 20%x =120
x*1 +20%x =120
x*(1+20%) =120
x*1,2 =120
x =120/1,2
x = 100
\(x+20\%x=120\)
\(\Rightarrow x+\frac{1}{5}x=120\)
\(\Rightarrow x.\left(1+\frac{1}{5}\right)=120\)
\(\Rightarrow x.\frac{6}{5}=120\)
\(\Rightarrow x=120:\frac{6}{5}\)
\(\Rightarrow x=100\)