Identify common factor: Identify if there is a common factor in the terms 2x2 and −162.Both terms are even, so they have a common factor of 2.Factor out the 2: 2(x2−81)
Factor out the common factor: Recognize that x2−81 is a difference of squares.x2=x×x=(x)281=9×9=92So, x2−81=(x)2−92
Recognize difference of squares: Use the difference of squares formula to factor x2−81.The formula is a2−b2=(a−b)(a+b).(x)2−92=(x−9)(x+9)
Use difference of squares formula: Combine the factored form of x2−81 with the common factor 2 that was factored out in Step 1.2(x2−81)=2(x−9)(x+9)
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