Question

Find two whole numbers whose sum is 60 and whose difference is 12

Answer 1

$\left \{ {\big{x+y=60} \atop \big{x-y=12}} \right. \\--------\\x+x=60+12\\2x=72\ /:2\\x=36\\\\x+y=60\ \ \ \Rightarrow\ \ \ y=60-x\ \ \ \Rightarrow\ \ \ y=60-36=24\\\\Ans.\ the\ numbers:\ 36\ \ and\ \ 24$