Question

What is the sum of: 12/z-5 + 12/z+4

Answer 1

Hint: find a common denominator

Answer 2

umm.. 20?

Answer 3

Wait, so it's not 12/(z-5)? It's 12/z -5?

Answer 4

\[\frac{ 12 }{ z-5 } + \frac{ 2 }{ z+4 }\]

Answer 5

Common denominator is not 20. You've got a somewhat idea in that you multiply but you're not multiplying the whole denominator.

Answer 6

I don't understand..... sorry, can you, like, re-word it, i'm kinda slow..

Answer 7

Just multiply the denominators to find common denominator

Answer 8

so i have to multiply z-5 and z+4?

Answer 9

Common denominator would be (z-5)(z+4)

Answer 10

then the numerator would be 14?

Answer 11

No if you multiply something to bottom, you multiply the same thing to the top or else you change the entire thing

Answer 12

So what would u multiply to 12?

Answer 13

oh, so is the answer, \[\frac{ 2(7z+19) }{(z-5)(z+4) }\]?

Answer 14

No (z+4) because ur multiplying the bottom by (z+4)

Answer 15

so, wait, the denominator is (z-5)(z+4)?

Answer 16

Yes, that's ur common denominator. Let me draw it out for u

Answer 17

would it be better if i give you the multiple choice answers?

Answer 18

12(z+4) +2(z-5) /(z+4)(z-5)

Answer 19

nothing your saying is one of the answers

Answer 20

14z+38 /common den.

Answer 21

14z + 38 / (z+4)(z-5)

Answer 22

that's not one of the answers..

Answer 23

24z-12 / common deno

Answer 24

12/(z-5) + 12/(z+4)

12 * (z+4) = 12z + 48
12 * (z-5) = 12z - 60

So 12z + 48 + 12z - 60 = 24z - 12.

Answer 25

24z - 12/(z-5)(z+4) OR 12(2z -1)/(z-5)(z+4). Either one should be the answer.