To factor the expression 1331x3 + 8y3, we can recognize that this is a sum of cubes. The general formula to factor a sum of cubes a3 + b3 is:
- (a + b)(a2 – ab + b2)
In this case, we can identify:
- a = (11x) (since 1331 = 113)
- b = (2y) (since 8 = 23)
Applying the sum of cubes formula:
- First, we compute:
- a + b = 11x + 2y
- a2 = (11x)2 = 121x2
- b2 = (2y)2 = 4y2
- ab = (11x)(2y) = 22xy
Putting it all together:
- The first factor becomes (11x + 2y)
- The second factor simplifies to:
- 121x2 – 22xy + 4y2
Thus, the fully factored form of the expression 1331x3 + 8y3 is:
(11x + 2y)(121x2 – 22xy + 4y2)
To summarize, identifying sums of cubes in algebraic expressions like 1331x3 + 8y3 allows us to factor them effectively using known algebraic formulas, leading to a clearer understanding of their structure and roots.