[tex] \\ \text{Let a represent the son's age today.}\\ \\ \text{now since the man's age today is 2 years more than three times the}\\ \text{age his son will be 5 years from now. So we have}\\ \\ \text{Man's age today = }3\times(\text{ son's age after 5 years})+2\\ \\ \Rightarrow \text{Man's age today}=3(a+5)+2\\ \\ \Rightarrow \text{ Man's age today}=3a+15+2\\ \\ \Rightarrow \text{Man's age today}=3a+17 [/tex]
So the expression for the man's age today is: 3a+17
[tex] \\ \text{Now if the age of his son now is 8 years, then the age of man is}\\ \\ =3(8)+17\\ \\ =24+17\\ \\ =41 \text{ years} [/tex]
So man's age today is: 41 years