Question 70780
Let h=Harold, j=jack, and d=dan. If Harold is twice as old as jack then you could write this relationship as
{{{2j=h}}}For instance if jack is 10, then harold is 20
And if jack is 3 years older than dan then it can be written as
{{{d+3=j}}}
And if harold's age is 5 times dan's age then
{{{5d=h}}}
First set the 2 h equations equal to each other
{{{2j=5d}}}Solve for d
{{{d=(2/5)j}}}
Then plug this equation of d into d of the equation d+3=j
{{{d+3=j}}}
{{{(2/5)j+3=j}}}Plug in {{{d=(2/5)j}}}
{{{3=j-(2/5)j}}}Subtract (2/5)j from both sides
{{{3=(3/5)j}}}subtract fractions
{{{3*(5/3)=j}}}solve for j
{{{j=5}}}
So jack is 5 years old, harold is 10, and dan is 2