Question

determine, para x= √2 e y= raiz cúbica de -8 o valor da expressão x² - y³ - 5xy + 4x - 10

Answer 1

Olá!
Se x = $\sqrt{2}$ e y = $\sqrt[3]{-8}$, temos:


2-(-8) + 10$\sqrt{2}$ + 4$\sqrt{2}$ - 10 = 14$\sqrt{2}$

Answer 2

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$Se~~x= \sqrt{2} ~~~~~~~~~~y= \sqrt[3]{-8} = \sqrt[3]{-2^3} =-2 \\ \\ x^{2} -y^3-5xy+4x-10= \\ \\ ( \sqrt{2} )^2-(-2)^3-5. \sqrt{2} .(-2)+4 \sqrt{2} -10= \\ \\ 2-(-8)+10 \sqrt{2} +4 \sqrt{2} -10= \\ \\ 2+8+14 \sqrt{2} -10= \\ \\\not 10-\not10+14 \sqrt{2} = \\ \\ 14 \sqrt{2}$