Answer:
To find the sum of a + b where a and b are rational number.
1. when a and b are natural numbers
just add them . for example a =3, b=8
then ,a + b = 11
2. When a and b are whole numbers,
simply add them . for example a= 0, b=8
a+ b = 0 + 8= 8
3. When a and b are integers
for example, a =-1 b=8,
a+ b= -1+ 8 =7,
a=-2, b= -8
a+ b= -2-8=-10
a= -6 , b=2
a+ b= -6 + 2= -4
a= 8, b= -2
a+ b= 8 +(-2) =6
I have written this because Rational number = [Integers{Whole number(Natural number)}]
now when a= Any fraction=
and b = Any fraction=
now ,

Find L.C.M of q and v
= if q and v are Co-prime , just multiply them to find their L.C.M.
For example 14,9. LCM=14×9=126
Otherwise, Find factors of q and v . Then take out common factors first and then multiply the remaining with with common factors.For example
q=12 and v=18
12 =2×2×3
18=2×3×3
common factor =2,3
non common=2,3
L.C.M= 2×2×3×3=36
Suppose LCM of q and v = r
then ,
=
= 
then ,
a + b=
-2m+4m+5=3
(-2m+4m)+(5)=3
2m+5=3
2m+5-5=3-5
2m=-2
2m/2=-2/2
m=-1
One serving is 3/4 cups of rice. To find out how many serving there are in 12 cups of rice, you divide 12 by 3/4. (When dividing fractions, don't ask why. Flip the second one over and multiply).
12/(3/4) = 12 *(4/3) = 48/3 = 16
There are 16 servings of rices in 12 cups.
8.75 + 0.50 =9.25 dollars spend but she has 16 dollars so 16 - 9.25 = 6.75 dollars left