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.

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

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

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

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 = 33 220 + 33 $253 after 5 years.

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 = 52.2 + 32 = 84.2 84.2 degrees Fahrenheit

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¢

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

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

Homework Pg. 27 1 – 8 all, 10 – 24 E