Question 1195826

 

let's Tommy's age be {{{t}}}, Jack 's age {{{j}}}, and Sadie's age {{{s}}} 

if Tommy is three years older than Jack, we have

{{{t=j+3}}}......eq.1


if Sadie is seven less than twice Jack’s age, we have
 
{{{s=2j-7}}}..............eq.2


if Sadie and Tommy are twins, then

{{{s=t}}}.............eq.3


=> so we have  {{{t=2j-7}}}..............eq.2a


then  from eq.1 and eq.2a we have

{{{j+3=2j-7}}}

{{{7+3=2j-j}}}

{{{j=10}}}


Jack is {{{10}}} years old
Tommy  is {{{13 }}}years old
Sadie  is{{{ 13 }}}years old