Question

3X² - 1|5 x +7, para x= -3​

Answer 1

$3{x}^{2} - \frac{1}{5}x + 7, \text{ para} \: x = - 3 \\ 3 \cdot {( - 3)}^{2} - \frac{1}{5}\cdot( - 3) + 7 = \\ \\ 3\cdot9 + \frac{3}{5} + 7 = \\ \\ 27 + \frac{3}{5} + 7 = \\ \\ \frac{138}{5} + 7 = \\ \\ \bf{ \frac{173}{5}} \: ou \: 34, 6$

Tmj! :)