Question

3b3 (7b2+5) me ajudem pfv to com dúvida só nelaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

Answer 1

$3 {b}^{3} (7 {b}^{2} + 5)$

Multiplique por cada um :

${b}^{3} \times {b}^{2} = {b}^{3 + 2} = {b}^{5}$

$21 {b}^{5} + 15 {b}^{3}$

Espero ter ajudado