SOLUTION: please someone help me.........I am not able to solve this question(x/8+y/5=31/40,in this equation above,if x and y are positive integers,what is the value of x+y ?

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Question 922143: please someone help me.........I am not able to solve this question(x/8+y/5=31/40,in this equation above,if x and y are positive integers,what is the value of x+y ?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
The equation can represent a line, and the equation has infinitely many solutions, so x+y is not any specific number. BUT you want INTEGERS x and y.

%28x%2F8%2By%2F5%29%2A40=31
5x%2B8y=31
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What happens if y is solved in terms of x and x is solved in terms of y?
8y=-5x%2B31
y=-%285%2F8%29x%2B31%2F8
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5x=31-8y
x=31%2F5-8y%2F5
x=-%288%2F5%29y%2B31%2F5
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What is sum, x+y?
-%288%2F5%29y%2B31%2F5-%285%2F8%29x%2B31%2F8..........

Maybe making a graph, identifying some integer (x,y) points, and finding x+y for each of those would be easier, but would it give you better information?