Question 1011523
{{{a}}} is now {{{4}}} times as old as {{{b}}}:
 {{{a=4b}}}.....eq.1
five years ago {{{a}}} was {{{7}}} times as old as {{{b}}} was then: 
{{{a-5=7(b-5)}}}....eq.2

solve the system:

 {{{a=4b}}}.....eq.1
{{{a-5=7(b-5)}}}....eq.2
------------------------------substitute {{{a}}} from eq.1 in eq.2

{{{4b-5=7(b-5)}}}....eq.2....solve for {{{b}}}

{{{4b-5=7b-35}}}

{{{35-5=7b-4b}}}

{{{30=3b}}}

{{{highlight(b=10)}}}-> the present age

 then {{{a=4b}}}=> {{{highlight(a=40)}}}-> the present age