Question

qual é o valor da expressão?​

Answer 1

Resposta:

4) x = 2

5) $7\sqrt{3}$

6) $7\sqrt{2}$

7) $4\sqrt{3}$

Explicação passo-a-passo:

4) Basta substituir:

$x = \frac{-(-7) + \sqrt{(-7)^{2} - 4.3.2}}{2.3}\\\\x = \frac{7 + \sqrt{49 - 24}}{6}\\\\x = \frac{7+\sqrt{25}}{6}\\\\x = \frac{7 + 5}{6}\\\\x = \frac{12}{6}\\\\x = 2$

5)

$5\sqrt{3} + \sqrt{12} = \\5\sqrt{3} + \sqrt{4.3} = \\5\sqrt{3} + 2\sqrt{3} = \\7\sqrt{3}$

6)

$\sqrt{8} + 10\sqrt{2} - \sqrt{50} = \\\sqrt{4.2} + 10\sqrt{2} - \sqrt{25.2} = \\2\sqrt{2} + 10\sqrt{2} - 5\sqrt{2} = \\7\sqrt{2}$

7)

$\sqrt{75} - 2\sqrt{12} + \sqrt{27} = \\\sqrt{25.3} - 2\sqrt{4.3} + \sqrt{9.3} = \\5\sqrt{3} - 2.2\sqrt{3} + 3\sqrt{3} = \\5\sqrt{3} - 4\sqrt{3} + 3\sqrt{3} =\\4\sqrt{3}$