Answer
$(y^5+7)(5y^5-6)$.
Work Step by Step
The given expression is
$=5y^{10}+29y^5-42$
We can write
$=5(y^5)^2+29x^5-42$
Substitute $y^5=u$.
$=5(u)^2+29u-42$
Simplify.
$=5u^2+29u-42$
Rewrite $29u$ as $35u-6u$.
$=5u^2+35u-6u-42$
Factor.
$=5u(u+7)-6(u+7)$
$=(u+7)(5u-6)$.
Substitute back $u=y^5$.
$=(y^5+7)(5y^5-6)$.
