1. The additive identity is 0. This is because adding 0 to anything leads to the same value. Example: 0+3 = 3.
2. An equation is where you have two expressions separated by an equal sign. In your case it would be "a mathematical sentence whose verb is 'equal' (=)"
3. The multiplicative identity is 1. Multiply 1 with any number and the result is that same number. Example: 1*7 = 7.
4. An open sentence is an equation that contains one or more variables. An example would be x+2 = 4. The reason why we call it open is because the true or false nature of the sentence is up in the air until we know what x is. If we knew that x = 3 for instance, then x+2 = 4 would be false since 3+2 = 4 is false. If we nailed down what x was then it would go from open to closed.
5. The symmetric property is that if a = b then b = a. Think of a mirror how the image reverses.
Answer:
a. 
b. 
Step-by-step explanation:
First, we need tot find a general expression for the amount of caffeine remaining in the body after certain time. As the problem states that every hour x percent of caffeine leaves the body, we must substract that percentage from the initial quantity of caffeine, by each hour passing. That expression would be:

Then, to find the amount of caffeine metabolized per hour, we need to differentiate the previous equation. Following the differentiation rules we get:

The rate is negative as it represents the amount of caffeine leaving the body at certain time.
Answer: 1625
Step-by-step explanation:
From the question, we are informed that Joe makes a map of his neighborhood for a presentation and that the scale of his map is 1 inch: 250.
Then, it should be noted that a 6.5 inches would represent:
= 6.5 × 250
= 1625
The answer is 1625
The answer to this question is 152,000!
Answer:
B and E
Step-by-step explanation:
A. -7 ÷ (-4) = -7/-4 = 7/4 = 1.75
B. -(3 ÷ 2) = -(1.5) = -1.5
C. -8/5 * (-5/8) = (8/5) * (5/8) = 1
D. -5/-3 = 5/3 ≈ 1.667
E. -9 ÷ 6 = -9/6 = -1.5