Question 965274
{{{A+B=11}}}
,
,
,
{{{2A+B/2=10}}}
{{{4A+B=20}}}
Subtract eq. 1 from eq. 2,
{{{4A+B-A-B=20-11}}}
{{{3A=9}}}
{{{A=3}}}
Then,
{{{3+B=11}}}
{{{B=8}}}
So,
{{{AB=3(8)}}}
{{{AB=24}}}