Question 179740
5s + 8y+=2540
s+y = 370 multiply by -5 & add.
-5s-5y=-1850
5s+8y=2540
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3y=690
y=390/3
y=230 ans.
s+230=370
s=370-230
s=140 ans.
proof:
5*140+8*230=2540
700+1840=2540
2540=2540