How to factor 1/2x^2 -1/812x218 so that factors of two or more terms contain no fractional coefficients?

2 Answers
Feb 8, 2018

1/8(2x-1)(2x+1)18(2x1)(2x+1)

Explanation:

"take out a "color(blue)"common factor of "1/8take out a common factor of 18

rArr1/8(4x^2-1)18(4x21)

4x^2-1" is a "color(blue)"difference of squares"4x21 is a difference of squares

•color(white)(x)a^2-b^2=(a-b)(a+b)xa2b2=(ab)(a+b)

rArr4x^2-1=(2x-1)(2x+1)4x21=(2x1)(2x+1)

rArr1/2x^2-1/8=1/8(2x-1)(2x+1)12x218=18(2x1)(2x+1)

Feb 8, 2018

1/818(2x+1)(2x-1)(2x+1)(2x1)

Explanation:

Factor:

1/2x^2-1/812x218

Simplify 1/2x^212x2 to (x^2)/2x22.

x^2/2-1/8x2218

The common denominator is 88. Multiply x^2/2x22 by 4/444 to convert the denominator to 88.

x^2/2xx4/4-1/8x22×4418

Simplify.

(4x^2)/8-1/84x2818

Combine the numerators into a common fraction.

(4x^2-1)/84x218

Express the numerator as a difference of squares:

(a^2-b^2)=(a+b)(a-b)(a2b2)=(a+b)(ab)

(2x)^2-1^2=(2x+1)(2x-1)(2x)212=(2x+1)(2x1)

Place the factorization over the denominator 88.

((2x+1)(2x-1))/8(2x+1)(2x1)8

Alternatively,

1/818(2x+1)(2x-1)(2x+1)(2x1)