Example

Factoring y3+8y^3 + 8

To factor the binomial y3+8y^3 + 8, use the sum of cubes pattern: a3+b3=(a+b)(a2ab+b2)a^3 + b^3 = (a + b)(a^2 - ab + b^2).

Step 1: Confirm the expression fits the pattern. It is a sum, and both terms are perfect cubes, since the first term is y3y^3 and the second term is 88, which is 232^3. Thus, it is a sum of two cubes.

Step 2: Rewrite the terms explicitly as cubes to identify the values for aa and bb: a=ya = y and b=2b = 2. y3+8=y3+23y^3 + 8 = y^3 + 2^3

Step 3: Substitute these values into the sum of cubes formula: (y+2)(y2y2+22)(y + 2)(y^2 - y \cdot 2 + 2^2)

Step 4: Simplify the expressions inside the trinomial to get the final factored form: (y+2)(y22y+4)(y + 2)(y^2 - 2y + 4)

Step 5: Verify the factorization by multiplying the factors together: (y+2)(y22y+4)=y(y22y+4)+2(y22y+4)(y + 2)(y^2 - 2y + 4) = y(y^2 - 2y + 4) + 2(y^2 - 2y + 4) =y32y2+4y+2y24y+8= y^3 - 2y^2 + 4y + 2y^2 - 4y + 8 =y3+8= y^3 + 8

The correct factored form is (y+2)(y22y+4)(y + 2)(y^2 - 2y + 4).

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Updated 2026-04-30

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