The document discusses order of operations and provides examples of solving expressions and equations using the proper order of operations. It also includes two word problems, one about predicting population decrease over time using an exponential function, and another about money added to a bank account each week.

1. Order of Operations

2. P arentheses E xponents M ultiplication D ivision A ddition S ubtraction

3. Parentheses can mean any of the following: ( ), [ ], or { } Even though we say addition before subtraction, they are equals. For example, let’s simplify the following: 8 – 6 + 2. Because subtraction comes first, I do 8-6, which is 2. Then I do 2 + 2, which is 4.  The same idea applies to multiplication and division.

4. = 3 + 16 – 8 = 19 – 8 = 11 = 36 + 7 – 21 = 43 – 21 = 22

5. = 5p + (-8p)(6) + 4p = 5p + (-48p) + 4p = -43p + 4p = -39p = -4y(2) + 15y = -8y + 15y = 7y **Notice that the variable is in the answer!!!

6. The population of purple zebras is currently 200,000, but is decreasing at a rate of 6% each year. Use P = 200000(0.94) t , where P is population and t is time in years, to predict the number of purple zebras left after 25 years. Do: P = 200000(0.94) 25 (I would use my calculator, and round to the nearest whole number) There will be approximately 42,582 purple zebras.

7. Yadier has a checking account. He started off with $35, and adds $20 each week. If m = 35 + 20w represents the amount of money, m, in the account after w weeks, find the amount Yadier has after 10 weeks. Do: m = 35 + 20(10) = 35 + 200 = 235 Yadier has $235 after 10 weeks.