answer
x = {-5, -⅓}
explanation
[tex]3 {x}^{2} + 16x + 5 = 0[/tex]
[tex]3 {x}^{2} + 15x + x + 5 = 0[/tex]
[tex]3x(x + 5) + 1(x + 5) = 0[/tex]
[tex](x + 5)(3x + 1) = 0[/tex]
[tex]x = - 5 \: or \: - \frac{1}{3} [/tex]
[tex]x = \{ - 5 \: , - \frac{1}{3} \}[/tex]
HOPE IT HELPS...