Algebra 1 unit test

On a number line, a number, b, is located the same distance from 0 as another number, a, but in the opposite direction. The number b varies directly with the number a. For example b = 2 when a = -2. Which equation represents this direct variation between a and b?

A. b = -a

If f(x) = 2x2 + 1, what is f(x) when x = 3?

19

A store offers packing and mailing services to customers. The cost of shipping a box is a combination of a flat packing fee of $5 and an amount based on the weight in pounds of the box, $2.25 per pound. Which equation represents the shipping cost as a function of x, the weight in pounds?

A. f(x) = 2.25x + 5

What is the slope of a line that is perpendicular to the line y = 8x + 5?

B. -1/8

Line CD passes through points C(3, -5) and D(6, 0). What is the equation of line CD in standard form?

B. 5x - 3y = 30

The velocity of an object in meters per second varies directly with time in seconds since the object was dropped, as represented by the table. The acceleration due to gravity is the constant of variation. What is the acceleration due to gravity of a falling object?

B. 9.8 m/s^2

Alejandro made an error in the steps below when determining the equation of the line that is perpendicular to the line 4x - 3y = -8 and passes through the point (3, -2). Alejandro made his first error in which step?

B. Step 2

Which set of ordered pairs represents a function?

B. {(3, -1), (7, 1), (-6, -1), (9, 1), (2, -1)}

Which equation represents the graphed function?

C. 3/2x - 3 = y

Which steps should be used to graph the equation below? y - 4 = (x + 2)

C. 1. Plot the point (-2,4).2. From that point, count left 3 units and down 1 unit and plot a second point.3. Draw a line through the two points.

What is the slope of a line that is parallel to the line shown on the graph?

C. 1/4

The table represents a linear function. What is the slope of the function?

C. 3

Which equation represents a line that passes through (2, -1/2) and has a slope of 3?

C. y + = 3(x - 2)

The point-slope form of the equation of the line that passes through (-9, -2) and (1, 3) is y - 3 = (x - 1). What is the slope-intercept form of the equation for this line?

C. y = 1/2x +5/2

The table shows the profit from a school book fair based on the number of books sold. What is the rate of change for the function represented in the table?

D. $1.50 per book

The graph shows the amount of money Miguel earns after working x hours. What is the rate of change of the amount earned with respect to hours worked for this function?

D. 13 dollars per hour

The graph shows the relationship between the volume of a rectangular prism and the volume of a square pyramid with an identical base and height. What is the slope of the line?

D. 3

Pauley graphs the change in temperature of a glass of hot tea over time. He sees that the function appears to decrease quickly at first, then decrease more slowly as time passes. Which best describes this function?

D. It is nonlinear because linear functions increase or decrease at the same rate.

What is the inverse of the function f(x) = x - 12?

D. h(x) = 4x + 48

The function h(t) = -16t2 + 28t + 500 represents the height of a rock t seconds after it is propelled by a slingshot. What does h(3.2) represent?

D. the height of the rock 3.2 seconds after it is propelled

For one month Siera calculated her home town's average high temperature in degrees Fahrenheit. She wants to convert that temperature from degrees Fahrenheit to degrees Celsius using the function . What does C(F) represent?

D. the temperature of C degrees Celsius converted to degrees Fahrenheit

Which graph shows a set of ordered pairs that represent a function?

Graph 3

Which is the graph of the equation ?

Graph D

What is the slope of a line that is perpendicular to the line y = x + 4?

The slope of the line is -1

Alejandra correctly wrote the equation y - 3 = (x - 10) to represent a line that her teacher sketched. The teacher then changed the line so it had a slope of 2, but still went through the same point. Which equation should Alejandra write to represent the new line?

y - 3 = 2(x - 10)