Question

3.09 Unit 3 Test: Part 2

Answer 1

1. If a and b are two real numbers, explain how you calculate the difference a - b. Be sure to include the following in your explanation:
(a) A description of the relationship between addition and subtraction(b) How you can use a number line to help with the calculation(c) How you can determine the sign of the result

(a) Subtraction is essentially addition where the sum is of a positive number and a negative number.

(b) You can put the point, -3 for example, on the numberline, then in order to find what -3 + 5 is, move up 5 places on the number(move right) towards the positive side. This is essentially -3 + 5

(c) In order to determine the sign of the result, all you have to do is see where you end up on the number line. If you are to the left of zero, then your sign is negative. If you end up to the right of the zero, then your sign is positive.


2. The ages of Sylvana's three daughters are consecutive even integers. The sum of their ages is 60. Write an equation that represents this situation. Then, find the age of each daughter.

n + n + 2 + n + 4

3n + 6

3n + 6 = 60
3n = 54
n = 18

The ages of the daughters are,

18, 20, 22

Answer 2

If I am incorrect or you have any criticisms, please explain below.