Question 310340
{{{x + y = 56}}}
{{{x - y = 18}}}
Add these 2 equations
{{{2x = 74}}}
{{{x = 37}}}
Use substitution:
{{{37 + y = 56}}}
{{{y = 56 - 37}}}
{{{y = 19}}}
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check answers:
{{{37 + 19  = 56}}}
{{{56 = 56}}}
OK
{{{37 - 19 = 18}}}
{{{18 = 18}}}
OK