Unit 5 CSA Review

Model 4

Example 4: The total cost, y, for x tickets to a sports game includes a

processing fee and a price per ticket. One customer bought 3 tickets for

$90, and another bought 7 tickets for $170. Which linear equation

represents the total cost y for x tickets?

Answer:

Make a table

tickets(x)

Price(y)

3

90

7

170

Use the calculator steps to

find m and b

Calculator Steps:

Step 1: Click "ON" Select the table

(beside Triangle)

Step 2: Replace "A" with "x"

Step 3: Replace "B" with "y"

Step 4: Type in the Data

Step 5: "Menu", "4", "1", "3"

Step 6: Select x' from dropdown for

"x List"

Step 7: Select y' from dropdown for

"y list"

Step 8: Click "OK"

Now plug it in the equation

y = mx + b

m = 20

b = 30

Hence y = 20x + 30

Unit 5 CSA Review

Model 1

Example 1:

Sarah and James are selling popcorn and cotton candy at the State

Fair. Sarah sold 3 bags of popcorn and 9 sticks of cotton candy for a

total of $75. James sold 8 bags of popcorn and 5 sticks of cotton

candy for a total of $67. What is the cost of popcorn and stick of cotton

candy?

Answer:

Variables:

Popcorn = P

Cotton Candy = C

Equations:

Sarah: 3P+9C = 75

James: 8P+5C = 67

Hint: Use the calculator

1. Go to Scratch pad

2. "Menu" , "7", "5"

3. "Menu", "7", "1", "1"

4. Enter #Rows = 2 and # Columns = 3,

click "Ok"

5. Type in the data as

3 9 75

8 5 67

6.Press "Enter"

The answer that you will get is 1

04

017

Hence cost of popcorn = $4
and cost of cotton candy = $7

Model 2

Example 2: What is the equation of the line that passes through the

points (2, 4) and (6, -2)?

Answer:

Use the calculator steps to find out " m " and "b"

Then plug in those values in y = mx + b

Calculator Steps:

Step 1: Click "ON" Select the table (beside Triangle)

Step 2: Replace "A" with "x"

Step 3: Replace "B" with "y"

Step 4: Type in the Data

Step 5: "Menu", "4", "1", "3"

Step 6: Select x' from dropdown for "x List"

Step 7: Select y' from dropdown for "y list"

Step 8: Click "OK"

m = -1.5 and b = 7

Answer is y = -1.5 x + 7

Model 3

Example 3: A piggy bank contains 30 coins made up of nickels and
dimes. The total value of the coins is $2.10. Which system of equations
can be used to determine the number of nickels, n, and dimes, d, in the
piggy bank?

Answer:

Variables:

Nickels = n

Dimes = d

Equations:

Coins: n + d = 30

Money: 0.05 n + 0.10 d = 2.10

Hint: Use the calculator

1. Go to Scratch pad

2. "Menu" , "7", "5"

3. "Menu", "7", "1", "1"

4. Enter #Rows = 2 and # Columns = 3,

click "Ok"

5. Type in the data as

1
1 30

0.05 0.10 2.10

6 .Press "Enter"

The answer that you will get is

1

0 18

0

1

12

Hence # nickels = 18

and # dimes = 12

Model 5

Example 5: Which of the following is an equation of the line parallel to

the y-axis that contains the point (200, 500)?

x

y

Parallel means the same

hence parallel to y - axis looks exactly like y

Since it is a vertical line

VUX

x = 200

Model 6

Example: The graph of line h is shown below. Which equation describes

a line perpendicular to line h that has a y-intercept at (0,3)?

Step 1: Find the slope of the given line

m = rise / run

m = 1

Since we need to find the perpendicular slope,

which is the opposite reciprocals

means change the sign and flip the number.

since original slope (m) = 1/1,

the perpendicular slope should be -1/1

it is actually -1.

y = -1x +3 (this 3 is from the point given)

Model 7

Example: Which graph best represents the solution set of 2x−4y >8 ?

Note: if the y number is negative then

the symbol flips.

Here the equation will be 2x - 4y < 8

Model 8

Example: A car's fuel level over time can be represented by the graph of

a linear function shown on the grid.

What is the rate of change of the fuel level with respect to the number of

miles driven?

Find the slope (m) from graph

m = rise / run

m = 100 / 1

m = 100

b = 50

Now plug in y = mx + b

y = 100x + 50

Model 11

Example:

Answer:
Calculator Steps:
Step 1: Click "ON" Select the table (beside Triangle)

Step 2: Replace "A" with "x"
Step 3: Replace "B" with "y"
Step 4: Type in the Data
Step 5: "Menu", "4", "1", "3"
Step 6: Select x' from dropdown for "x List"

Step 7: Select y' from dropdown for "y list"

Step 8: Click "OK"

Now plug it in the equation

y = mx + b

Model 9

Example: Mark is starting a lawn mowing business. He plans to charge

a base fee of $15 plus $12 per hour. Write an equation that represents
the total cost, y, for x hours of work.

Answer: Here look for the key words per which represents the slope (m)

hence m = 12

and the y - intercept (b) = 15

Now plug it in the equation y = mx + b

y = 12x + 15

Model 10

Example: What is the equation in slope-intercept form of the line that

passes through the point (3,7) and has a slope of 4?

m

y = 4(x - 3) + 7

y = 4x - 12 + 7

y = 4x - 5