Question 1172542
{{{system(A=2E,A-12=3(E-12))}}}


{{{2E-12=3E-36}}}

{{{36-12=E}}}

.


.

__________________________________________________________________________


{{{system(x+y=50,5x+10y=400)}}}


{{{system(x+y=50,x+2y=80)}}}

Eq2-Eq1 gives you {{{y=30}}}, making that {{{x=20}}}.