Cross-Multiplication and Ratios

The video tutorial explains how to determine if two ratios are equal by cross-multiplying. It provides four examples, demonstrating both equal and unequal ratios, including cases with decimals. The method involves multiplying diagonally across the ratios and comparing the results. This approach is useful for quickly checking ratio equivalence without finding a common denominator.

What is the method used to check if two ratios are equal?

• Dividing the numerators by the denominators

• Subtracting the smaller ratio from the larger

• Cross-multiplying the terms

• Adding the numerators and denominators

What is the first step in checking if two ratios are equal?

• Add the numerators

• Cross-multiply the terms

• Subtract the smaller ratio

• Find a common denominator

In the first example, what are the two ratios being compared?

• 6:12 and 1:3

• 6:12 and 1:2

• 3:6 and 1:2

• 6:12 and 2:4

What is the result of cross-multiplying the ratios 6:12 and 1:2?

• 12 and 6

• 6 and 6

• 12 and 12

• 24 and 12

Why might finding a common denominator not always be the best method?

• It requires a calculator

• It only works for fractions

• It can be time-consuming with large numbers

• It is too simple

What is the result of multiplying 12 by 1 in the first example?

• 24

• 6

• 12

• 18

What is the result of multiplying 6 by 2 in the first example?

• 12

• 6

• 24

• 18

In the second example, what are the two ratios being compared?

• 2:4 and 4:8

• 2:3 and 4:6

• 1:2 and 2:4

• 3:6 and 6:12

What is the result of cross-multiplying the ratios 2:4 and 4:8?

• 16 and 16

• 8 and 16

• 4 and 8

• 12 and 12

What is the result of multiplying 4 by 4 in the second example?

• 8

• 20

• 16

• 12