Question 1071651
a mans age and his sons add to 45 years.<pre>M + S = 45</pre>Five years ago the man was six times as old as his son.<pre>M - 5 = 6(S - 5)</pre>How old was the man when his son was born?<pre>{{{system(M+S=45,M-5=6(S-5))}}}

Simplify the second equation and solve the system for
for M and S, by either substitution or elimination 
(addition).

Then subtract the son's age from the man's age to find
out how old the man was when the son was born.

Edwin</pre>