# Unit 1: Linear Systems of Equations

Chapter 1

Chapter 1.1: Video Lesson on Modelling with Linear Equations      Part 1         Part 2         Part 3

Chapter 1.3:  Video Lesson on Solving Linear Systems by Graphing       Part 1         Part 2

Chapter 1.5:  Video Lesson on Ways that Two Lines Can Intersect            Lesson

Chapter 1.8:  Video Lesson on Method of Substitution           Part 1          Part 2

Chapter 1.9:  Video Lesson on Method of Elimination           Part 1          Part 2

Questions for you to Try

1.      Solve the following systems of equations by the method of substitution

a)   y = 3x + 10     and     y = -5x - 6                 Answer:   (-2,4)              Video Solution

b)   4x - y - 18 = 0  and  2x + 3y + 12 = 0         Answer:   (3, -6)             Video Solution

c)   4x - 3y + 24 = 0   and    x + 6y - 3 = 0        Answer:   (-5, 4/3)          Video Solution

2.     Solve the following systems of equations by the method of elimination

a)   2x + y + 1 = 0    and    3x + 2y + 3 = 0      Answer:   (1, -3)              Video Solution

b)   5x - 3y - 9 = 0    and    4y + 9x = 82          Answer:   (6, 7)               Video Solution

c)   5/2 x  +  2/3 y  +  2 = 0    and    1/2 x  +  3/4 y = 7         Answer:   (-4, 12)       Video Solution

3.      Tyra went to the corner store and purchased one popsicle and one chocolate bar for \$3.25.  The next day she purchased four popsicles and three chocolate bars for \$11.00.  How much does one popsicle cost?

4.      Charlie's age and Fred's age add to 44.  Thirteen years ago, Charlie was twice as old as Fred.  How old is Charlie now?                 Answer:  25                            Video Solution

5.      Farmer Ted has chickens and cows on his farm.  There are 130 animals and 340 legs.  How many cows are there?