Grouping Terms: Group terms to make factoring easier.We can group the terms as follows: 2r3−r2 + 20r−10.
Factor Out Common Factors: Factor out the greatest common factor from each group.From the first group 2r3−r2, we can factor out r2, giving us r2(2r−1).From the second group 20r−10, we can factor out 10, giving us 10(2r−1).
Identify Common Factor: Notice that both groups now have a common factor of (2r−1).We can factor out (2r−1) from the entire expression.This gives us (2r−1)(r2+10).
Check Factored Form: Check the factored form by expanding it to ensure it matches the original polynomial.(2r−1)(r2+10)=2r3+20r−r2−10=2r3−r2+20r−10.The expanded form matches the original polynomial, so the factoring is correct.