Question 253251
Father's Age = F
Son's Age = S

{{{F-3=4S
{{{FS=351}}}
{{{F=351/S}}}
{{{F-3=(351/S)-3=4S}}}
{{{(351/S)-3=4S}}}
{{{((351-3S)/S)=4S}}}
{{{351-3S=4S^2}}}
{{{0=4S^2+3S-352}}}

*[invoke quadratic "x", 4, 3, -351]

Son's age is 9, Father's age is 39