Question

Factorise 3b5 − 12b

Answer 1

${<strong>3b^5-12b:\quad 3b\left(b^2+2\right)\left(b^2-2\right)}$

$3b^5-12b$

$=3b\left(b^4-4\right)$

$=3b\left(b^2+2\right)\left(b^2-2\right)$