Question

o valor numérico da expressão:
2√xy - √x² -21y
para y 3
para x 12

Answer 1

$PAra\to~~y=3~~e~~x=12\\\\\\ 2 \sqrt{xy} - \sqrt{x^2-21y} \to\\\\ 2 \sqrt{12.3} - \sqrt{12^2-21.3} \to\\\\ 2 \sqrt{36} - \sqrt{144-63} \to\\\\ 2.6- \sqrt{81} \to\\\\ 12-9\to\\\\ \large\boxed{\boxed{3}}$