Question 940008

Pete is {{{5}}} years older then Mary.

{{{Pete=Mary+5}}}

  {{{5}}} Years ago Pete was {{{twice}}} as old as Mary

{{{Pete-5=2(Mary-5)}}}


{{{Pete-5=2Mary-10}}} ...substitute {{{Pete=Mary+5}}}

{{{Mary+5-5=2Mary-10}}}

{{{Mary=2Mary-10}}}

{{{10=2Mary-Mary}}}

{{{10=Mary}}}

{{{Mary=10}}}

and {{{Pete=10+5}}}=> {{{Pete=15}}}