Question 611642
{{{x + y = 63}}}
{{{y = x + 7}}} substitute into the equation above
{{{x + (x+7) = 63}}}
{{{2x + 7 = 63}}}
{{{2x = 56}}}
{{{x = 28}}}
So y = x + 6 = 28 + 7 = 35

Does 35 + 28 = 63??