Question 1133056

let’s Richard’s age be {{{R}}} and André’s  age be {{{A}}}

Four years ago, Richard was {{{R-4}}} years old and André {{{A-4}}} years old

Richard is three times the age of his son André:

{{{R-4=3(A-4)}}}
{{{R-4=3A-12}}}
{{{R=3A-12+4}}}
{{{R=3A-8}}}..........eq.1


 In {{{10}}} years, Richard will be {{{R+10}}} years old and André {{{A+10}}} years old
and  Richard will be twice André’s age


{{{R+10=2(A+10)}}}
{{{R+10=2A+20}}}
{{{R=2A+20-10}}}
{{{R=2A+10}}}.........eq.2


from eq.1 and eq.2 we have

{{{3A-8=2A+10}}}
{{{3A-2A=8+10}}}
{{{A=18}}}


go back to eq.1


{{{R=3A-8}}}..........eq.1 substitute {{{18}}} for {{{A}}}

{{{R=3*18-8}}}

{{{R=54-8}}}

{{{R=46}}}



Richard’s is {{{46}}} and André’s  is {{{18}}} old now