Let n be the number. The difference of the number and six is n-6. Then three times the difference of the number and six is 3·(n-6). This number 3·(n-6) increased by four times the number n, then
3·(n-6)=4·n.
Solve it:
3·n-3·6=4n,
3n-4n=18,
-n=18,
n=-18.
Answer: n=-18 and expression is 3·(n-6)=4·n.
