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If a = \(\frac{2x}{1 - x}\) and b = \(\frac{1 + x}{1 - x}\),...

If a = \(\frac{2x}{1 - x}\) and b = \(\frac{1 + x}{1 - x}\), then a2 - b2 in the simplest form is

A.

\(\frac{3x + 1}{x - 1}\)

B.

\(\frac{3x^2 - 1}{(x - 1)}\)2

C.

x\(\frac{3x - 2}{1 - x}\)

D.

\(\frac{3x^2 - 1}{(x - 1)}\)

Correct answer is A

a2 - b2 = (\(\frac{2x}{1 - x}\))2 - (\(\frac{1 + x}{1 - x}\))2

= (\(\frac{2x}{1 - x} + \frac{1 + x}{1 - x}\))(\(\frac{2x}{1 - x} - \frac{1 + x}{1 - X}\))

= (\(\frac{3x + 1}{1 - x}\))(\(\frac{x - 1}{1 - x}\))

= \(\frac{3x + 1}{x - 1}\)