Question

Determine os valores de X e de y nos seguintes feixes de paralelas

Answer 1

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$\frac{4}{10} = \frac{x}{y} \\ \\ Se~~x+y=21 \\ x=21-y \\ \\ \frac{4}{10} = \frac{21-y}{y} \\ \\ 4y=10(21-y) \\ 4y=210-10y \\ 4y+10y=210 \\ 14y=210 \\ y=210\div14 \\ \\ \fbox{ y=15 } \\ \\ se~~x=21-y \\ x=21-15 \\ \\ \fbox{ x=6 }$