Question 1117893
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<pre>
{{{(x+y)/4}}} = 10  implies  x + y = 40.


3*(x-y) = 18  implies  x - y = 6.


So you have these two equations

x + y = 40
x - y =  6
--------------------Add them to get  x = 23,  y = 17.
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Solved.