document.write( "Question 1151155: Three years ago a father was thrice as old as his son in 5 years time the father will be twice as his son what will be the sum of their age in four years \n" ); document.write( "
Algebra.Com's Answer #772787 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
let f = father's present age, let s = son's
\n" ); document.write( ":
\n" ); document.write( "write an equation for each statement, simplify
\n" ); document.write( ":
\n" ); document.write( "Three years ago a father was thrice as old as his son
\n" ); document.write( "f - 3 = 3(s-3)
\n" ); document.write( "f - 3 = 3s - 9
\n" ); document.write( "f = 3s - 9 + 3
\n" ); document.write( "f = 3s - 6
\n" ); document.write( " in 5 years time the father will be twice as his son
\n" ); document.write( "f + 5 = 2(s+5)
\n" ); document.write( "f + 5 = 2s + 10
\n" ); document.write( "f = 2s + 10 - 5
\n" ); document.write( "f = 2s + 5
\n" ); document.write( "replace f with 3s - 6, from the 1st statement
\n" ); document.write( "3s - 6 = 2s + 5
\n" ); document.write( "3s - 2s = 5 + 6
\n" ); document.write( "s = 11 yrs is the son's age
\n" ); document.write( "find the fathers age
\n" ); document.write( "f = 3(11) - 6
\n" ); document.write( "f = 33 - 6
\n" ); document.write( "f = 27 yrs is the father's age
\n" ); document.write( ":
\n" ); document.write( "what will be the sum of their age in four years
\n" ); document.write( "27+4 + 11+4 = 46 \n" ); document.write( "
\n" );