Adding and subtracting fractions?

Question

Subtract

12
----
z

minus

10
----
z



Adding fractions

9
--
s

+

9
---
s^2

Help

Answer 1

12/z-10/z
2/z

9/s+9/s^2
9s/s^2+9/s^2
(9s+9)/s^2

Answer 2

You just have to give the fractions the same denominator.
The first problem already has the same denominator in the two fractions.
12/z - 10/z = 2/z (Subtract the numberators. This isn't much different than 12 apples - 10 apples = 2 apples. It's the same idea as 12 fiftieths - 10 fiftieths = 2 fiftieths.

The second problem ... multiply numerator and denominator of 9/s by s ... 9s/s^2

Now the first fraction has the same denominator as the second.
9s/s^2 + 9/s^2 = (9s + 9)/s^2

Answer 3

for the first one since they have the same denomenator subtract numorator. giving you 2 over z
for the sencond you have to create a common denomenator so multiply 9 over s by s then add the numorators. you should get 9s+9 over s^2

Answer 4

12/z - 10/z = (12-10)/z = 2/z

9/s + 9/(s^2) = 9*s/(s*s) + 9/(s^2) = 9(s+1)/s^2

Answer 5

2/z

(9s+9)/s^2