Let \(b=\) Ben's age
Let \(d=\) Daniel's age
We know:
\(b=d+20\)
and
\(b-3=3(d-3)\)
Plug the value of \(b\) into the second equation:
\((d+20)-3=3(d-3)\)
\(\rightarrow d+17=3d-9\)
\(\rightarrow-2d+17=-9\)
\(\rightarrow-2d=-26\)
\(\rightarrow d=13\)
Since Ben is 20 years older than Daniel, Ben is 13+20=33 years old.
