7.4 hw answers
DESCRIPTION
7.4 HW Answers. (4, -1). (19, 16). 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. (5, 3). (5, 6). (-½, -2). (-7, -12). (9, -3). (2, 1). (-10, -5). (4, 4). 10x + 2y = 155. 12x + 3y = 189. $14.50 balls. $5 bags. (-2, -2). x = -19 + 9. x = -10. 5(y + 9) – 3y = 7. y = -19. (-10, -19). - PowerPoint PPT PresentationTRANSCRIPT
1.
2.
3.
4.
5.
(4, -1)
(5, 3)
(-½, -2)
(9, -3)
(-10, -5)
6.
7.
8.
9.
10.
(19, 16)
(5, 6)
(-7, -12)
(2, 1)
(4, 4)
Scoring Your Homework• Count how many problems you missed
or didn’t do
• 0-1 missed = 10• 2-3 missed = 9• 4-5 missed = 8• 6-7 missed = 7• 8-9 missed = 6
• 10-11 missed = 5• 12-13 missed = 4• 14-15 missed = 3• 16-17 missed = 2• 18-19 missed = 1• 20-21 missed = 0
Table of Contents
Topic Page #...7.1 Solve Systems By Graphing 767.2 Solve Systems By Substitution 777.3 Solve Systems By Combination 787.4 Multiplication w/ Combination 797.5 System Word Problems 80
1. You are selling tickets to a play. The price of a student ticket is $5, and the price of an adult ticket is $8. You sell 556 tickets and you collect $3,797. How many adult and student tickets did you sell?
Step 1: Choose your variables
S = student ticketa = adult ticket
1. You are selling tickets to a play. The price of a student ticket is $5, and the price of an adult ticket is $8. You sell 556 tickets and you collect $3,797. How many adult and student tickets did you sell?
Step 2: Write two equations:A) One that represents the value of the items
5s + 8a = 3797B) One that represent the quantity of items
s + a = 556
Step 3: Solve the system using substitution or elimination
5s + 8a = 3797s + a = 556(–8)
5s + 8a = 3797
-8s – 8a = -4448+
s = 217 -3s = -651217 + a = 556
a = 339
2. A bag contains dimes and nickels. There are 18 coins in the bag. The value of the coins is $1.25. How many of each type of coin is in the bag?
Step 1: Choose your variables
d = # dimesn = # nickels
2. A bag contains dimes and nickels. There are 18 coins in the bag. The value of the coins is $1.25. How many of each type of coin is in the bag?
Step 2: Write two equations:A) One that represents the value of the items
0.10d + 0.05n = 1.25B) One that represent the quantity of items
d + n = 18
Step 3: Solve the system using substitution or elimination
0.10d + 0.05n = 1.25
d + n = 18(–5)10d + 5n = 125
-5d – 5n = -90+
d = 7 5d = 357 + n = 18
n = 11
(100)
3. Kylie has 4.50 in dimes and quarters. She has 3 more dimes than quarters. How many quarters does she have?
d = # dimesq = # quarters0.10d + 0.25q = 4.50
d = q + 3
0.10(q + 3) + 0.25q = 4.500.10q + 0.30 + 0.25q = 4.50
0.35q + 0.30 = 4.50
0.35q = 4.20q = 12
= 12 + 3 = 15
4. An adult ticket to a school play costs $5 and a student ticket costs $3. A total of $460 was collected from the sale of 120 tickets. How many student tickets were purchased?
a = adult tickets = student ticket5a + 3s = 460
a + s = 120
5. A drummer goes to Guitar Center and buys drum sticks and brushes. The wood sticks that he buys are $10.50 a pair, and the brushes are $24 a pair. He buys twice as many pairs of wood sticks as brushes, and ends up spending a total of $90. How many pair of sticks and brushes did he buy?
d = drum sticksb = brushes10.50d + 24b = 90
d = 2b
6. The sophomore class is selling pretzels and popcorn at a school event to raise money for a dance. They charge $2.50 for a bag of popcorn and $2 for a pretzel. They collect $336 during the event. They sell twice as many bags of popcorn as pretzels. How many pretzels do they sell?
z = pretzelsp = popcorn
2.50p + 2z = 336p = 2z
7. You went to Home Depot and bought two types of plants. One type was a flowering plant while the other was non-flowering. The flowering plant cost $3.20 each and the non-flowering plant cost $1.50 each. You purchased a total of 24 plants for $49.60. How many of each type of plant did he buy?
f = flower plantn = non-flower
3.20f + 1.5n = 49.60f + n = 24