1. Lesson: 1- 5 A Plan For Problem Solving
Applied Algebra B
Lesson: 1- 5
A Plan For Problem Solving
Objective: Learn to use a four-step plan to solve problems.

2. Four Step Plan Explore Plan Solve Examine Read the problem
Select a strategy for the problem
Solve
Use your strategy
Examine
Check your answer.

3. Formula
An equation that states a rule for the relationship between quantities.
Name a formula you know.

4. Interest I = prt Interest formula I = interest p = principal
r = interest rate, written as a decimal
t =time in years

5. Example I = prt $253 after 5 years.
Suppose you deposit $220 into an account that pays 3% simple interest. How much money would you have in the account after 5 years?
Explore: what do we know?
I = prt
Plan: what to do to solve
Solve: work out the problem
I = 220(0.03)(5)
Check: is the answer reasonable?
I = 33
$253 after 5 years.

6. On your Own
User F = 1.8C + 32 to change degrees Celsius C to degrees Fahrenheit F. Find the temperature in degrees Fahrenheit if it is 29 degrees C.
F = 1.8(29) + 32 =
= 84.2
84.2 degrees Fahrenheit

7. Example There are 12 ways to make 25¢
How many ways can you make 25¢ using dimes, nickels, and pennies?
Coin
Number
Dimes 2 1
Nickels 3 5 4
Pennies 10 15 20
There are 12 ways to make 25¢

8. Property Summary Commutative Associative Identity a + b = b + a
(a + b) + c = a + (b + c)
(ab)c = a(bc)
Identity
a + 0 = 0 + a = a
a*1 = 1*a = a

9. Property Summary Zero Distributive Substitution a*0 = 0*a = 0
a(b + c) = ab + ac
a(b – c) = ab – ac
Substitution
If a = b then a may be substituted for b

10. Homework
Pg – 8 all, 10 – 24 E