Presentation on theme: "Halloween Warm-Up Paul has two dozen Halloween cookies. He will eat three cookies on Sunday. On every day that follows, he will eat a number of cookies."— Presentation transcript:
1Halloween Warm-UpPaul has two dozen Halloween cookies. He will eat three cookies on Sunday. On every day that follows, he will eat a number of cookies that is one greater than the day before. On what day will he find that he doesn’t have enough cookies to follow this procedure?
2Answer Thursday Sun -3 Mon- 4 Tues- 5 Wed -6 18 cookies eaten = 6 cookies left over, but on Thursday he needs to eat 7 cookies to continue his pattern.
4Rules to RememberWhen solving an equation, the goal is to get the variable by itself.Addition and Subtraction are inverse operations. (opposites)Multiplication and Division are inverse operations. (opposites)
5Don’t ForgetThe equation is like a balance scale. Whatever you do to one side of the equation must be done to the other side of the equation.
6How to solve two-step equations “Undo” the operations in the reverse order of the order of operations.You are using the work back-words strategyIn order of operations we do multiplication or division first, then addition and subtraction. When solving an equation we do the opposite!
7Integer Rules to Remember Adding IntegersSame sign= add and keep the signDifferent sign = subtract and keep the sign of the larger numberSubtracting IntegersKeep, Change, ChangeFollow the rules for additionMultiplying and Dividing IntegersSame Sign = Positive AnswerDifferent Sign = Negative Answer
8Let’s Try One… 3x + 2 = 23 - 2 -2 21 3x = 21 3 3 x = 7 213x = 21x = 7The problem contains addition and multiplication. Which one do we undo 1st?
9Another Example -2y – 7 = 3 +7 +7 10 -2y = 10 -2 -2 y = -5 10-2y = 10y = -5The problem contains subtraction and multiplication. Which one do we undo 1st?
10Last Example -3c + 9 = 3 -9 -9 -6 -3c = -6 -3 -3 c = 2 -6-3c = -6c = 2The problem contains addition and multiplication. Which one do we undo 1st?