Question 829077
You mean their sum equals 58?
Let {{{A}}} and {{{B}}} be your numbers.
{{{A+B=58}}}
{{{A-B=12}}}
Add the two equations together.
{{{A+B+A-B=58+12}}}
{{{2A=70}}}
{{{highlight(A=35)}}}
Then use either equation to solve for B,
{{{35+B=58}}}
{{{highlight(B=23)}}}