Algebra I Test
Sections 3.5 – 3.8
In Detroit the temperature is 69˚ F and is rising at a rate of 2˚ per hour. In Atlanta the temperature is 84˚ F and is falling at a rate of 3˚ per hour. If the temperatures continue to change at the same rates, how long will it be before the temperatures are the same?
1. Write an equation for the model.
69 + 2x = 84 – 3x
2. Solve the equation mathematically.
x = 3 hours
3. Fill in the table to double check your answer.
Hours / 1 / 2 / 3 / 4 / 5 / 6 / 7Detroit / 71 / 73 / 75 / 77 / 79 / 81 / 83
Atlanta / 81 / 78 / 75 / 72 / 69 / 66 / 63
The school newspaper is 11¼ inches wide. The staff wants the stories to be in 3 columns with ¼ inch between each. The margins on each side of the paper are ¾ inch.
4. Draw a picture and label the column widths as x.
5. Write an equation to find the width of each column.
¾ + x + ¼ + x + ¼ + x + ¾ = 11¼
6. How wide should each column be?
X = 3 1/12
Round the following numbers according to directions
Number / Tenths / Hundredths41. 9638 / 42.0 / 41.96
-41.8491 / -41.8 / -41.85
12.49999 / 12.5 / 12.50
-44.5500 / -44.5 or -44.6 / -44.55
Solve the equation. Round the result to the nearest hundredth place.
15. 2x + 8 = -26
x = -17
16. 4(3 – 7x) = 19
x = -.25
17. 2.3 x + 4.8 = 9.3
x ≈ 1.96
18. -5.89x + 7.5 = 2.18
x ≈ .90
19. 2.5 – 3.6x = 18.4 + 23.7x
x ≈ -.58
Solve the equation for the indicated variable
20. C = 2πr solve for r
r= c2π
21. d = rt solve for r
r= dt
22. V= 13πr2h solve for h
h= 3vπr2 or v13πr2
23. F= 59C+32 solve for C
C=95(F-32)
24. 2W + 2L = P solve for L
L= P-2w2
Rewrite the equation so y is a function of x (solve for y)
25. y + 2x = 14
y = 14 – 2x
26. 12y + 10x = 81
y= 81-10x12
27. -2x + 5y – 6 = -11
y= -5+2x5
28. 2- y6 = 8x
y=12-48x
29. 4x + 2(y – 3) = 10
y=8-2x
30. 6x – 5(y – 2) = 4x + 10
y= 25x
Find the unit rate for each (round to the nearest penny)
31. $3 for 5 cans of corn $.60 / can
32. $2.39 for 12 apples $.20 / apple
33. 32 ounces for 8 servings 4 oz / serving
Find the average speed
34. Fly 780 miles in 3 hours 260 miles / hour
35. Walk 2 miles in ¼ hour 8 miles / hour
36. Swim 3 km in 30 minutes 6 km / hour or .1 km / minute
You have recorded your car mileage and gas used for several weeks
Week / 1 / 2 / 3 / 4Miles / 300 / 187 / 225 / 268
Gallons / 12.6 / 7.3 / 9.4 / 10.8
37. Find the average consumption in miles per gallon.
About 24.44 miles / gallon
38. Use your answer to find out how many miles you could drive on 15 gallons.
About 366 miles
39. While visiting Italy you want to change $48 for liras. The rate of exchange is 1850 lira per US dollar. How many liras will you receive?
48 dollars1x1850 lira1 dollar=88,800 lira
Pledge:______