SOLUTION: The following problem was on my final exam last night, and I cannot figure this out. I am trying to simplify this equation: [3 + b(to power of -1)] over [2 + b(to power of -1)

Algebra ->  Radicals -> SOLUTION: The following problem was on my final exam last night, and I cannot figure this out. I am trying to simplify this equation: [3 + b(to power of -1)] over [2 + b(to power of -1)      Log On


   



Question 248679: The following problem was on my final exam last night, and I cannot figure this out. I am trying to simplify this equation:
[3 + b(to power of -1)]
over
[2 + b(to power of -1)]
What I did was turn the b to -1 power into 1 over b. Rewrite equation as
(3 + 1 over b)
over
(2 + 1 over b)
Then I multiplied out to remover the denominator of b in each part of the overall equation. Rewrite equation as
3b+1
over
2b+1
Then i multiplied out to remove the denominator of 2b+1. Rewrite as:
(3b+1) (2b+1) which is also 6b squared + 2b + 3b + 1. Rewrite as:
6b squared + 5b + 1.
Is this correct??

Found 2 solutions by jim_thompson5910, stanbon:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
You were doing great until you decided to multiply by 2b%2B1. If this were an equation, then you could do that (to both sides). However, you cannot do that here unless you balance that action out by also dividing by 2b%2B1. So you really don't get anywhere in terms of simplification (as it makes things worse). So you're just best off stopping at the point where you got %283b%2B1%29%2F%282b%2B1%29


So or in short, %283%2Bb%5E%28-1%29%29%2F%282%2Bb%5E%28-1%29%29=%283b%2B1%29%2F%282b%2B1%29


You can verify your answer with a graph (ie the graphs of the original and the final expressions should be the same).


Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
[3 + b(to power of -1)]
over
[2 + b(to power of -1)]
================================
[3 + (1/b)]/[2 + (1/b)]
---
[(3b+1)/b] / [(2b+1)/b]
---
Invert the denominator and multiply:
[(3b+1)/b] * [b/(2b+1)]
---
Cancel the "b" factor which is common to numerator and denominator:
---
= (3b+1)/(2b+1)
=====================
Cheers,
Stan H.