Answer
$7r^3s(4rs+1-5rs^2)$
Work Step by Step
The GCF of the coefficients is $7$.
The GCF of the literal coefficients (the variables) is the one with the lowest exponent for each variable.
Thus, the GCF of the variables is $r^3s$.
The GCF is $7r^3s$.
Factor out the GCF to obtain:
$28r^4s^2+7r^3s-35r^4s^3=7r^3s(4rs+1-5rs^2)$
