Question

[Phương Nguyễn]

Tìm a:

       a  x \(\frac{1}{5}\)+  80%  x  a  = 2015 2015,15

      làm ơn giúp mình

Answer 1

[Phạm Trà Giang]

\(a\cdot\frac{1}{5}+80\%\cdot a=20152015,15\)

\(\Rightarrow a\cdot\frac{1}{5}+\frac{4}{5}\cdot a=20152015,15\)

\(\Rightarrow a\cdot\left(\frac{1}{5}+\frac{4}{5}\right)=20152015,15\)

\(\Rightarrow a\cdot1=20152015,15\Rightarrow a=20152015,15:1=20152015,15\)