Question 1205458


let Jack’s age be {{{x}}} and Jack’s father age {{{y}}}
if Jack’s father is three times as old as Jack, we have 

{{{y=3x}}}...eq.1

if five years ago, the sum of there ages was {{{34}}}, we have

{{{(y-5)+(x-5)=34}}}...eq.2

substitute {{{y }}}from eq.1

{{{3x-5+(x-5)=34}}}...solve for {{{x}}}
{{{3x-5+x-5=34}}}
{{{4x-10=34}}}
{{{4x=34+10}}}

{{{x=44/4}}}
{{{x=11}}}

go to
{{{y=3x}}}...eq.1, substitute x

{{{y=3*11}}}

{{{y=33}}}

Jack’s father is {{{33}}} years old now