Question 138378
English to math symbols translations in parentheses:


The sum (+) of two numbers (x, y) is (=) 20, or {{{x+y=20}}}


Their (x, y) difference (-) is (=) 4, or {{{x-y=4}}}


Add the two equations:  {{{(x+y)+(x-y)=20+4}}}



Remove the parentheses and collect like terms:  {{{2x+0y=24}}}, or {{{2x=24}}}


Divide by 2: {{{x=12}}}


Since {{{x=12}}}, {{{12-y=4}}}, so {{{y=8}}}