[tex]\frac { 3ax }{ 5 } -4c=\frac { ax }{ 5 } [/tex] First multiply both sides by 5: [tex]5\cdot (\frac { 3ax }{ 5 } -4c)=5\cdot \frac { ax }{ 5 } \\ 3ax-20c=ax[/tex] then take the ax to the other side : [tex]3ax-20-ax=0[/tex] and simplify: [tex]2ax-20c=0[/tex] factor: [tex]2(ax-10c)=0\\ ax-10c=0\\ ax=10c\\ x=\frac { 10c }{ a } [/tex]
