Question

Resolva as equações.
A) $\times + \frac{30}{ \times } = 17$

B) $\times + \frac{ \times }{3} = - 7$

C) $\sqrt{ \times - 2 = 7}$
​

Answer 1

(a)

$x + \dfrac{30}{x} = 17\Rightarrow \dfrac{2x + 30}{x} = 17 \\ 2x + 30 = 17x\Rightarrow 15x = 30\Rightarrow x = 2$

(b)

$x + \dfrac{x}{3} = - 7\Rightarrow \dfrac{3x + x}{3} = - 7 \\ 4x = - 21\Rightarrow x = - \dfrac{21}{4}$

(c)

$\sqrt{x - 2} = 7\Rightarrow {( \sqrt{x - 2} )}^{2} = {7}^{2} \\ x - 2 = 49\Rightarrow x = 51$