Thursday, February 5, 2015

How do I factor this problem?14x^2-56

You need to decompose the coefficients such that:


`14 = 1*2*7`


`56 = 1*2^3*7`


You need to write the expression using the factored form of coefficients, such that:


`2*7x^2 - 2^3*7`


You should notice that there exists the common factor `2*7` , hence, you may factor out `2*7` , such that:


`2*7(x^2 - 2^2)`


You need to convert the difference of squares `x^2 - 2^2` into a product, using the following formula, such that:


`a^2 - b^2 = (a-b)(a+b)`


Reasoning by analogy yields:


`x^2 - 2^2 = (x - 2)(x + 2)`


Hence, evaluating the factored form of the given expression, yields `14x^2 - 56 = 14(x - 2)(x + 2).`

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