Identify Expression Type: Identify the type of expression and the possible factoring technique.The expression 1+r9 is a sum of two terms. One of the terms is a perfect power of r. We can consider if it's possible to apply a sum of cubes or a sum of higher powers factoring technique.
Recognize Perfect Cube: Recognize that r9 is a perfect cube, as r9=(r3)3. The expression can be rewritten as 13+(r3)3, which resembles the sum of cubes formula a3+b3=(a+b)(a2−ab+b2).
Apply Sum of Cubes Formula: Apply the sum of cubes formula to factor the expression.Using the formula, we have:1+r9=13+(r3)3=(1+r3)(12−1⋅r3+r6).
Simplify Factored Expression: Simplify the factored expression.Simplifying the second factor, we get:(1+r3)(1−r3+r6).
Check Further Factoring: Check for further factoring possibilities. The second factor 1−r3+r6 does not factor further using standard algebraic identities or methods for polynomials. Therefore, the expression is fully factored.
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