
This statement can be represented as
, since the quotient is the answer to a division problem.
Divide. 
Multiply. 
Simplify. When the numerator and denominator are the same, the fraction is equal to 1. 
The process and the answer is shown in the following picture. The five ones are all the same.
45 is what percent of 190
45/190 = 0.2368
Make it into a percentage
0.2368 * 100 = 23.7
23.7% of the food is from fat
It should be 15. 88 minus 28 is 60. Then 60 divided by 4 is 15.
The total number of gifts = x+y.
The inequality is:

Key chains cost $1, Magnets $0.50
Total Cost = x + 0.5y
Inequality is:

Without graphing you can solve system by using substitution:

This is one solution where the maximum x value is given.
So the most keychains that can be purchased is 16. However, because magnets are cheaper, more can be purchased as long as cost remains under 20.
If you solve both inequalities for "y", you get the upper and lower bounds for how many magnets can be purchased given a quantity of keychains.

This is complete solution which gives all possible combinations.
(Graph is Attached)