1. Warm-up 4-3 The sum of two numbers is -63. The first number minus the second is -41. Find the numbers.

2. Lesson 4-3: Word Problems Objective: Students will: Use systems of equations to model and solve word problems

3. Translation Example 1 Twice a number added to a 2 nd number is eleven. Twice the second number, added to the first number, equals 1. Find the numbers?

4. Mixture Q 1 V 1 + Q 2 V 2 = Total, where Total = Q Total V Total Usually use elimination Example 2 30% fat cream is mixed with 2% fat milk to make 100 gallons of milk that is 4% fat. How much of cream and 2% milk should be used?

5. Distance D 1 = r 1 t 1 D 2 = r 2 t 2 All distance problems → Find a relationship between 1 and 2 Usually D’s Usually use substitution Example 3 Agnes walks at 3 mph. Four hours later Fred bikes at 15 mph to catch her. How long until Fred catches her?

6. Age x = age now y = 2 nd age now 3 years from now5 years ago x + 3x – 5 y + 3y – 5 Example: Fred is 8 years older than his sister. 4 years ago his sister was 2/3 as old as Fred. How old are they now?