Sect 2.4 notes.notebook
October 20, 2015
Date: Sect 2.4 Obj: To solve equations with variables on both sides. To identify equations that are identities or have no solution. Complete the SOLVE IT problem on the top of page 102. Expression to represent the population of Town A: Expression to represent the population of Town B: Solution: When solving equations you need to separate the variable and the constant terms. Variable term:
2x, 3y, 4m Constant term: 3, 6, ‐17 Separate means to put the variable terms on one side of the equal sign and the constants on the other. Ex 1: 5x + 10 = 15x Step 1: Subtract 5x. Why? Step 2: Ex 2: For this problem it will be a good idea to develop a plan before beginning to solve the problem. Decide which side of the equal sign you will put the constants and which side you will put the variables. C
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5w + 12 = 7w – 4 Step 1: Choose which side to put the variables and which side to put the constants. Step 2: Check each term to see if it belongs where it is at. If not, add or subtract to put that term on the other side of the equation. Sect 2.4 notes.notebook
October 20, 2015
Ex 3: ‐3c – 12 = ‐5 + c Ex 4: Suppose you can rent a car from Hertz for either $25 a day plus $0.45 a mile or for $40 a day plus $0.25 a mile. What number of miles results in the same cost for one day? Let m = Equation: Ex 5: ‐2(y – 22) = ‐4(y + 12) Some equations have no solution. That is, no value of the variable results in a true sentence. The solution set is the empty set. Ex 6: 3n + 4 =5(n + 2) – 2n