Question

Find two mixed numbers so that the sum is 16 and the difference is 5

Answer 1

See, pls, suggested decision:

If suppose, that 1-st number is 'x' and the 2-d is 'y', it is possible to make up system of equations:
$\left \{ {{x+y=16} \atop {x-y=5}} \right. \ =\ \textgreater \ \ \left \{ {{x=10.5} \atop {y=5.5}} \right.$

Answer 2

10 1/2 and 5 1/2
Because 10+5=15 and 1/2+1/2=1
15+1 =16
10 1/2 - 5 1/2
10-5 =5 and 1/2 - 1/2=0
So the answers are 10 1/2 and 5 1/2