Algebra I - Midterm Practice

6) An internet business sells U.S. flags for $16.95 each, plus $2.50 shipping per flag. Shipping is free, however, on orders where more than $100.00 worth of flags is purchased. Which equation/inequality correctly shows the number of flags f that must be purchased to get free shipping?

16.95 f > 100

4) Evaluate the expression (3y-11)/x when x = 2 and y = 5.

2

Find the second, fourth, and eleventh terms of the sequence. A(n)= 5 + (n - 1)(-3)

2 , -4, -25

Start with the equation: 2x - 3 = 11 Step 1: 2x - 3 + 3 = 11 + 3 Step 2: 2x = 14 Step 3: (1/2) (2x) = (1/2)(14) Step 4: x = 7 True or False? In Step 3, the symmetric property of equality was applied?

False.

How does changing the value of b affect the graph of an equation in the form y = mx + b?

It will shift the graph up or down.

1) An equation is in the form y = mx + b. What does the coefficient in the equation represent? What does the constant in the equation represent?

The coefficient represents the rate of change, and the constant represents the point where the line crosses the y‐axis

A certain child's weight was measured at 16.6 pounds. The child then gained weight at a rate of 0.65 pounds per month. On a graph of weight versus time, what would 0.65 pounds/month represent?

The slope of the graph.

Start with the equation: 2x - 3 = 11 Step 1: 2x - 3 + 3 = 11 + 3 Step 2: 2x = 14 Step 3: (1/2) (2x) = (1/2)(14) Step 4: x = 7 True or False? In Step 1, the addition property of equality was applied?

True

10) Sam is beginning an exercise program that begins the first week with 30 minutes of daily exercise. Each week, daily exercise is increased by 5 minutes. Which function represents the number of minutes of daily exercise in week n?

f(1) = 30; f(n) = 5(n - 1) + 30, for n ≥ 2

To fix a clogged pipe, Dripmaster Plumbing charges $75 plus $40 per hour. NoClog Plumber charges $50 plus $70 per hour for the same service. Which function shows the difference in charges between the two companies for a repair taking h hours?

f(h) = $25 - $30h

The potential energy P of an object relative to the ground is equal to the product of its mass m, the acceleration due to gravity g, and its height above the ground h. P = mgh

h = P/(mg)

A worker has dug 3 holes for fence posts. It will take 15 minutes to dig each additional hole. Which rule represents the time t it will take to dig the additional holes needed to have a total of n post holes?

t = 15(n ‐ 3)

3) Solve the equation y = mx + b for x.

x = (y-b)/m

2) Since 2005, the amount of money spent at restaurants in the United States has increased about 7% each year. In 2005, about $360 billion was spent at restaurants. Write a function that represents the situation. Let x = the number of years since 2005, and y = the annual amount spent at restaurants (in billions of dollars).

y = (360)(1.07)^x

11) The domain of ݂y = -1.5x + 4 is {1, 2, 3, 4}. What is the range?

{‐2, ‐0.5, 1, 2.5}