Question 58381
d = Devon's age
j = Jamies age
{{{j + d = 30}}}
{{{(j - 10)(d - 10) = 24}}}
{{{jd -10d -10j + 100 = 24}}}
{{{j(30 - j) - 10(30 - j) - 10j + 76 = 0}}}
{{{30j - j^2 - 300 + 10j - 10j + 76 = 0}}}
{{{-j^2 + 30j - 224 = 0}}}
use the formula
{{{j = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
{{{j = (-30 +- sqrt( 30^2-4*(-1)*(-224) ))/(2*(-1)) }}}
{{{j = (-30 +- sqrt( 900 - 896 ))/ -2 }}}
{{{j = (-30 +- sqrt( 4 ))/ -2 }}}
{{{j = (-30 +- 2)/ -2 }}}
{{{j = 15 +- 1}}}
j = 16,14
{{{j + d = 30}}}
if j = 16, then d = 14
if j = 14, then d = 16
The problem said Jamie was younger than Devon, so
Jamie is 14 and Devon is 16