Warm-Up:

• Put the following equations into y= mx + b form:

a) 2y + 14x = 6 b) -3y – 4x – 15 = 0

Warm-Up: Problem of the Day

• Given the equation: , come up with a second equation to create a linear system that has:

A) One solution B) No solution C) Infinite solutions

3y 9x 15

Unit 1Using Substitution to Solve Word Problems

Learning Goal: I can model a word problem using a linear equation and solve a linear system algebraically

using substitution

Word Problems – Example 1

• Two taxi companies charge as follows:– Drive Right: $3 plus $0.20/km– Pick Up: $5 plus $0.15/km

• At what distance will both companies charge the same amount?– Define 2 variables and write a system of equations to

model this situation– Solve this system using substitution

Word Problems – Example 2

• Julie has dimes and quarters in her pocket. She has 24 coins in total. If the number of dimes is 3 less than twice the number of quarters, find the number of each type of coin.– Define 2 variables and write a system of equations to

model this situation– Solve this system using substitution

Homework

• Pg. 93 # 14, 16, 17, 18• More challenging: Pg. 93 # 20, 21ab, 25