Question

Resolva: a) $(\frac{40}{x} )+5=15$ e b) $5^{x} -10=115$

Answer 1

$a) \\ \\ \frac{40}{x} + 5 = 15 \\ \\ \\ \\ \frac{40}{x} + \frac{5x}{x} = \frac{15x}{x} \\ \\ \\ 40 + 5x = 15x \\ \\ \\ x = \frac{40}{10} \\ \\ \\ x = 4 \\ \\ \\ b) \\ \\ {5}^{x} - 10 = 115 \\ \\ \\ {5}^{x} = 125 \\ \\ \\ {5}^{x} = {5}^{3} \\ \\ \\ x = 3$