[tex] \frac{6}{10} *a+80=a\\
(aducem~tot~la~acelas~numitor~sa~scapam~de~numitor)\\
6a+800=10a\\
6a-10a=-800\\
-4a=-800\\
a=-800:(-4)\\
a=200\\\\
Facem~proba:\\
\frac{6*200}{10} +80=200\\
\frac{1200}{10} + \frac{800}{10} = \frac{2000}{10} \\
\frac{2000}{10} = \frac{2000}{10}
[/tex]