\(\frac{x}{7}=\frac{y}{6}và2x-y=20\)
Ta có\(\frac{x}{7}=\frac{2x}{14}=\frac{y}{6}=\frac{2x-y}{14-6}=\frac{20}{8}=\frac{5}{2}\)
\(=>x=\frac{5}{2}.7=\frac{35}{2}=17.5\)
\(=>y=\frac{5}{2}.6=15\)
\(x+y=17.5+15=32.5\)
TICK CHO MINK NHOA
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