2r3-5r2-6r+15r-3

Group the first two terms and the last two terms.

(2r3-5r2)-6r+15r-3

Factor out the greatest common factor (GCF) from each group.

r2(2r-5)-3(2r-5)r-3

r2(2r-5)-3(2r-5)r-3

Factor the polynomial by factoring out the greatest common factor, 2r-5.

(2r-5)(r2-3)r-3

Simplify (2r^3-5r^2-6r+15)/(r-3)