# Algebraic fractions: [(2x+3)/5] - [(5x+2)/8] +1 = 0, etc

#### Monkeyseat

##### Full Member
This question is driving me crazy.

[(2x+3)/5] - [(5x+2)/8] +1 = 0

How do I do this?

I took the one across to the other side, then multiplied by the LCM 40 and went from there. I got x = 26/-9.

Please someone show me I've been doing this for ages and can't.

EDIT:

Better shot here:

I've done them all apart from 8, 13, 14 and 15. If you could help me with the other 3 that would also be great as I'm having trouble getting started.

Thank you.

#### Monkeyseat

##### Full Member
Yes I have done number 8! It was 6. I just missed off a minus sign somewhere when moving numbers to another side. Anyway if you could help me with 13, 14 and 15 that would be very much appreciated.

#### Monkeyseat

##### Full Member
I have also done question 15 and got 43 after I realised how to set it out. Still not sure on the other 2 though. Please help. Just 13 and 14.

Cheers.

#### Subhotosh Khan

##### Super Moderator
Staff member
What is the definition of perimeter of a rectangle?

What is the expression of the fourth-side in terms of the other three side (described in the problem)?

#### Denis

##### Senior Member
Re: Algebraic fractions

Hints:
13: 3 sides = 6x + 3; so 4th = (6x + 3) / 3

14: (7a - 3) / 8 - a/3 = 11

#### Monkeyseat

##### Full Member
Ok I think I've done it.

For 13 I got 123/24 or 5.125 and for 14 I got 21. I was kind of setting it out the right way already but e.g. for number 14 I did 1/3 not a/3 before. Are both those answers right?

Thanks for your hints Dennis it helped a lot. For the shape one I didn't really get completely what Subhotosh Khan is saying but thank you anyway. I just did [(6x+3)/1] + [(6x+3)/3] = 45. Were you saying something like that?

#### Denis

##### Senior Member
Monkeyseat said:
For the shape one I didn't really get completely what Subhotosh Khan is saying but thank you anyway. I just did [(6x+3)/1] + [(6x+3)/3] = 45. Were you saying something like that?
Yes, Mr K was saying exactly that...

"Sorry for posting so many questions, I'm rubbish at math"
If you post that again, you get NO help: you're not rubbish :shock: