USING CROSS PRODUCTS TO SOLVE PROPORTION

Solve the proportions using the Cross Product Property.

Problem 1 :

Solution:

Use Cross Product Rule,

3x = 2 × 21

3x = 42

x = 42/3

x = 14

Problem 2 :

Solution:

Use Cross Product Rule,

20b = 8 × 50

20b = 40

b = 40/20

b = 2

Problem 3 :

Solution:

Use Cross Product Rule,

2.5d = 8 × 0.5

2.5d = 4

d = 4/2.5

d = 1.6

Problem 4 :

Solution:

Use Cross Product Rule,

3m = 5 × 21

3m = 105

m = 105/3

m = 35

Problem 5 :

Solution:

Use Cross Product Rule,

4x = 9

x = 9/4

x = 2.25

Problem 6 :

Solution:

Use Cross Product Rule,

9(30 + a) = 8 × 45

270 + 9a = 360

9a = 360 - 270

9a = 90

a = 90/9

a = 10

Problem 7 :

Solution:

Use Cross Product Rule,

26(70 - w) = 15 × 104

1820 - 26w = 1560

-26w = 1560 - 1820

-26w = -260

w = 260/26

w = 10

Problem 8 :

Solution:

Use Cross Product Rule,

9a = a + 24

9a - a = 24

8a = 24

a = 24/8

a = 3

Problem 9 :

Solution:

Use Cross Product Rule,

14n = 2(n + 30) 

14n = 2n + 60 

12n = 60

n = 60/12

n = 5