1. Start by identifying what the question wants so we are looking for miles per 1 gallon.
2. Set up a statement. When the word “per” is being used it relates to a fraction or a ratio. In this question we need to find how many miles a single gallon will give us. So set it up as miles/gallons
3. Plug in your numbers. Now our statement is 13 miles/15 gallons
4. Calculate. So do 13/15 which equals 0.86 miles per 1 gallon.
Tip: always add in words into your calculations. Mainly the units you are using so you can quickly look and know what the units will be. This will help you in upper placement math as well
Answer:
19
Step-by-step explanation:
21 - 2 is 19
The number of days in which the air quality index exceed 100 in the year 1988 is 75 days. Then the correct option is B.
<h3>What is a function?</h3>
The function is an expression, rule, or law that defines the relationship between one variable to another variable. Functions are ubiquitous in mathematics and are essential for formulating physical relationships.
The air quality index (AQI) is given by the function.

Where n be the number of days the AQI exceeds 100 in a given year.
For
, then we have

More about the function link is given below.
brainly.com/question/5245372
Substitute the given point (3, -2) in each condition
(i) y < -3; y ≤ (2/3)x - 4
-2 < -3 → False
Therefore, it is not a solution.
[Since the values of x and y must satisfy both the conditions, if one of them does not satisfy the condition then it is not necessary to check the other one.]
(ii) y > -3; y ≥ 2/3x - 4
-2 > -3 → True
y ≥ 2/3x - 4
-2 ≥ -2 → True
Therefore, it is a solution.
(iii) y < -3; y ≥ 2/3x - 4
-2 < -3 → False
Therefore, it is not a solution.
(iv) y > -2; y ≤ 2/3x - 4
-2 > -2 → False
Therefore, it is not a solution.
Thereofore, the system of linear inequalities having the point (3, -2) in its solution set is y > -3; y ≥ 2/3x - 4. Hope it helps you.