Question 1149644
x, younger girl
16-x, older girl


{{{16-x-x=2}}}
{{{16-2x=2}}}
{{{8-x=1}}}
{{{x=7}}}




ALTERNATIVE
x, younger
M, older
{{{system(x+M=16,M-x=2)}}}


{{{highlight_green(x=16-M)}}}
-
{{{highlight_green(M=x+2)}}}