Question

2x/(4x+2) x (14x+7)/6 and 5/(x-2) - 3/(x-2).

I got both of these problems wrong on my quiz and I can't understand why. For the second problem, I assume 2/(x-2) would be the simplest answer but that wasn't one of the choices. Can anybody explain these problems to me?

Answer 1

do some factoring 1st

\[\frac{2x}{2(2x + 1)} \times \frac{7(2x +1)}{6} \]

you may see you can cancel 2 in the numerator and denominator of the 1st fraction and (2x + 1) will cancel

leaving the answer

\[\frac{7x}{6}\]

Answer 2

the 2nd question, both fractions have the same denominator and you can factor the denominator.

so you get


\[\frac{5}{(2x -2)} - \frac{3}{(2x - 2)} = \frac{5 - 3}{2(x -1)}\]

you just need to simplify it by cancelling a common factor.

Answer 3

Wow, the first one so simple. I feel stupid. The second one, though, is not one of the answer choices. They're listed here: http://oi44.tinypic.com/8xm1ea.jpg

Answer 4

for the 2nd question, is one of the denominators x+2??
if so, which one is it??

Answer 5

Not unless the teacher made a typo, which I possible.

Answer 6

i think so.........