A proportion looks like this:

It means that the quantity a,b,c and d are in the same proportion: the ratio between a and b is the same ratio between c and d.
They are particularly useful in situation when you have an example given, and you want to extrapolate the relationship for another couple.
For example, you can think of the following problem: "Five apples cost 2 dollars. How much will 8 apples cost?"
You can build the proportion

And then solve it for x:

Answer:
The simplified form of the given expression is 12(m -n).
Step-by-step explanation:
The given expression is

We need to simplify the given expression.
Rearrange the terms according to the variables.

On combining like terms, we get

On simplification, we get


Taking GCF common.

Therefore the simplified form of the given expression is 12(m -n).
Answer:
Step-by-step explanation:
Objects that float on water have densities less than the density of water; those that do not float on water have densisties greater than the density of water:
Float on water: d < 0.0361 lb/in³ (where d denotes denisity)
Do not float on water: d > 0.0361 lb/in³
Answer:
3.08 x 
Step-by-step explanation:
3080 = 3.08 x 1000 = 3.08 x 