Question

Rational expressions? Help please!! D:

Answer 1

Two fellow students, Theo and Paula, have added two rational expressions. They ended up at different answers so they have asked you to check their work. Please explain to them any errors that you find.

Answer 2

2. Wally knows that in order to add or subtract rational expressions, he has to find the least common denominator first. Unfortunately, he can not remember how to do that. Using complete sentences, explain to Wally how to find least common denominators. Make sure you clearly explain any important items to consider.

Answer 3

I'm not very good at math (it's my worst subject) and this is my last assignment on my online algebra II class. Help is appreciated! :)

Answer 4

@spheeaal Theo's mistake is in the second step where he multiplied the top of the expression on the left by (x+2). First of all it is not necessary to do that multiplication because the expression at the bottom (x-5)(x+2) is already the common denominator and therefore there is no need to multiply this expression by any factor. Secondly, any time you multiply the top you should also multiply the bottom to preserve the ratio. Theo only multiplies the top and not the bottom and therefore he has altered the ratio.

Paula's mistake is in the fourth step where she factors x^2-4x-5 into (x+2)(x-5) which is wrong factoring. Also, factoring is not needed here. Since the denominators of the two expressions is the same the numerator can be added. The mistake continues in the next step where she cancels out factors across an addition. You cannot do that. There is a plus sign between the two expressions and common factors cannot be cancelled out across addition or subtraction.

Answer 5

Ahh, wow! Thank you so much!!! I've been trying to do this assignment for a while now and I haven't really been able to understand it. Thank you!!!! :)

Answer 6

welcome @spheeaal!