9.1b Solving by Substitution continued
1. 2x + 3y = 11
5x – y = –15
– 6y + 8 = –x
3. Write a linear system to represent each situation.
a) The sum of two numbers is six, and the difference is 10
b) A desktop computer begins downloading an 885-megabyte (MB) file at 35 MB/s.
At the same time, a laptop begins downloading a 1450 MB file at a rate of 60 MB/s.
c) During a performance by a theatre company, the main act was on stage for 3 min
less than twice the time of the opening act. Together, the two acts performed for 30
min.
Ch 8 & 9 Systems of Equations Page 1
d) A box contains 23 coins consisting of dimes and quarters. There is a total of$3.35
in the box.
5. A 127 m cable is cut into two pieces. One piece is 46 m
longer than twice the other. What is the length of each piece?
6. Patrick has $167 and earns $15 each day. Sarah has $95 and earns
$23 each day. In how many days will Patrick have as much money as
Sarah?
7. Karen's aunt is 36 years older than Karen. In 7 years their age will
combine to 70. How old are they now?
Ch 8 & 9 Systems of Equations Page 2
8. Jessica has 32 nickels and quarters that have a value
of $4.20. How many of each coin does she have?
Assignment p475 #9-14,16,17,19,24
Ch 8 & 9 Systems of Equations Page 3