Question

1. Write the function that should be graphed in order to solve the equation 9x−6=−8
.(2 points)
f(x)=

x+

Question 2
______________________________________________________________________________________________________________________________

Use the graph below to answer the question:

Four points are plotted on a coordinate plane, forming two intersecting lines.

What is the solution to the equation 2x−1=4x+3
?

(1 point)
x=


Question 3
You are traveling home from work. You are decreasing the distance as you walk home. Your house is 41 blocks away, and you walk 3 blocks per minute. Create a linear equation that represents the situation. (3 points)
Linear equation: y=
−

x

How many minutes will it take, to the nearest minute, to get home?

minutes (round to the nearest whole minute)

Question 4
_____________________________________________________________________________________________________________________________

Use the image to answer the question below.

A line is graphed on a coordinate plane.

A water tank is being slowly emptied to remove it and replace it with another one. The graph shows the declining water level of gallons in hours. Approximately how long will it take for the water tank to be emptied?

(1 point)
Responses

-3.0 hours
-3.0 hours

11.7 hours
11.7 hours

12.0 hours
12.0 hours

35.0 hours
35.0 hours

Answer 1

Question 1
- Graph y = 9x − 6 and y = −8. (The solution is their intersection.)
- So f(x) = 9x − 6. (Intersection with g(x)=−8 gives 9x−6=−8 ⇒ x = −2/9.)

Question 2
2x − 1 = 4x + 3
2x − 4x = 3 + 1
−2x = 4 ⇒ x = −2

Question 3
Let y be blocks remaining and x be minutes:
y = 41 − 3x
Set y = 0: 41 − 3x = 0 ⇒ x = 41/3 ≈ 13.667 ≈ 14 minutes

Question 4
The tank is empty where the graph crosses the time (x) axis, at about 12.0 hours.