Download 2.1 Proportions Name Solve each proportion by showing all work. 1

2.1 Proportions
Name ______________________________
Learning Objective: A.CED.1
A.CED.1
A.CED.3
A.REI.1
A.REI.3
I will create a proportion to find sales tax and discount and solve it
I will create a proportion from a word problem and solve it
I will identify the constraints on a word problem
I will solve a proportion by using cross multiplication
I will solve a proportion
Solve each proportion by showing all work.
1.
3 12

8
x
2.
n 63

8 3
3.
5
x

2 12
4.
2 12

3 4x
Show all your proportions and label your answers to get full credit.
5. A car travels 350 miles on 20 gallons of gasoline. How many gallons will be used to travel 875
miles under the same conditions? Round to nearest whole number.
6. The ratio of oil to vinegar in a certain salad dressing is 8 : 5. How much oil must be blended with 7
liters of vinegar for that recipe? Round to nearest whole number.
7. If 1 gallon of paint covers 450 square feet, how many gallons are needed to paint a room with 675
square feet of wall surface? Round to nearest tenth.
8. Two out of five students in the ninth grade have braces. If there are 650 students in the
ninth grade, how many have braces? Show your proportion and solve.
Solve each proportion by showing all work. Round answers to the nearest tenth when necessary.
9.
2x  4
 8
6
10.
3x  5
2
7
11.
x4
 9  8
2
12.
3x  15
 4  10
9
13.
2x  5
 7  12
3
14.
3x  7
 16
5
15.
 3x  9
 6  18
6
16.
2x  4
 4  12
3
17.
1
4

6x
15
18.
2
2x  3

15
9
19.
21
3
y8
20.
7
n4

4
8
21.
2
1

2x  1 5
22.
n 4
3

5
2
23.
6
7

14
x3
24.
n5
3

4
2
Answers: 1)
32
9) –26
3) 30
11) 30
5)
350 875

, x = 50 gal of gas
20
x
13) 10
15) 27
17) 0.6
7)
19) 15
1
x

, x = 1.5 gal of paint
450 675
21) 4.5
23) 19.3