2-9 Problem Solving

Objective: To explore problem situations, and to translate verbal sentences and problems into equations or formulas and vice versa.

Drill #30

1.

2.

3.

4.49

25

1004

259

164

Explore the problem

Shane has 4 dimes more than quarters and 7 fewer nickels than dimes. If Shane has 28 coins total, how many nickels dimes and quarters does he have?

Problem Solving Plan **(24.)1. Explore the problem• What is the problem asking• What information are you given2. Plan the solution• Define variables• Set up equations3. Solve the problem4. Examine the Solution• Does the answer makes sense? • Check your answer

Explore the problem

Strategies for working out problems

• Draw a diagram

• Make a table

• Guess and check

• Look for a pattern

• Work backwards

• Solve a simpler problem

Example 1 pg 127

Defining the Variable **(25.)

Definition: choosing a variable to represent one of the unspecified numbers in the problem.

Example:

Sam is ten years older than Mary.

Sam = s

Mary = m

m + 10 = s

Words that indicate equality

• Is

• Equals

• Is equal to

• Is the same as

• Is as much as

• Is identical

Formula**(26.)

Definition: an equation that states a rule or relationship between certain quanities.

NOTE:

Examples:

A = ½ bh V = l(w)(h)

d = rt P = 2l + 2w

Exercise 9,13 pg 130

Write a problem

b = Brittany’s height

b + 5 = Tatiana’s height

2b + (b + 5) = 194

Write a problem based on this information.

Write an expression to represent the area of the shaded region

5. 6.

a

b

3

2

c

ds

t

Write an equation that represents the situation below if the two lines

are the same length.

7.

30 x

8 xx