Question

calcule o valor de x³-y³, sabendo que x+y =12,5 e x-y=4 ? ​

Answer 1

Resposta: 484,75

$|x+y=\frac{125}{10}|\\|x-y=4|\\x+x+y-y=\frac{125}{10}+4\\2x=\frac{165}{10}\\20x=165\\x=\frac{165}{20}\\\boxed{x=\frac{33}{4}}=8,25\\\\8,25-y=4\\y=8,25-4\\y=4,25\\\boxed{y=\frac{425}{100}}\\\\\\(y)^{3}-(y)^{3}\\(\frac{33}{4})^{3}-(\frac{425}{100})^{3}\\\\(\frac{35937}{64})-(\frac{76765625}{1000000})\\(561,515625)-(76,765625)=\boxed{484,75}$

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