Question 41
Algebraic ExpressionsFind the missing numerator: 5/(x + 1) − 3/(1 − x) − (7x − 1)/(x2 − 1) = ______/(x + 1)
- A.−1
- B.x − 1
- C.3(1 − 5x)/(x + 1)
- D.3(1 − 5x)
- E.1.
Show the answer and explanation
Answer: E (1.)
Explanation
−3/(1 − x) = 3/(x − 1). Over x² − 1 the top is 5(x − 1) + 3(x + 1) − (7x − 1) = x − 1, so the whole is (x − 1)/(x² − 1) = 1/(x + 1).