Solving Proportions and Cross Products

The video tutorial explains how to solve proportions using cross products. It begins with an introduction to the concept of cross products in proportions, followed by a detailed walkthrough of two example problems. The first example involves solving a proportion with numbers 15, 6, 9, and x, while the second example uses 91, 63, 47, and x. The teacher demonstrates how to set up the cross products, solve for x, and round the result if necessary.

What is the main method used to solve proportions in this video?

• Dividing cross products

• Multiplying cross products

• Subtracting cross products

• Adding cross products

What is the first step in solving a proportion using cross products?

• Add the numbers

• Subtract the numbers

• Multiply the cross products

• Divide the cross products

Why must cross products of a proportion be equal?

• To make the calculation easier

• To ensure the proportion is balanced

• To simplify the equation

• To increase the accuracy

In the first example, what are the cross products?

• 15 and x, 6 and 9

• 15 and 6, x and 9

• 15 and 9, 6 and x

• 15 and 6, 9 and x

What equation is formed by the cross products in the first example?

• 9x = 15 - 6

• 9x = 15 / 6

• 9x = 15 + 6

• 9x = 15 * 6

How do you solve for x in the equation 9x = 90?

• Subtract 9 from both sides

• Add 9 to both sides

• Divide both sides by 9

• Multiply both sides by 9

What is the value of x in the first example?

• 6

• 15

• 10

• 9

What is the result of 15 * 6 in the first example?

• 85

• 80

• 90

• 95

What are the cross products in the second example?

• 91 and x, 63 and 47

• 91 and 47, x and 63

• 91 and 63, 47 and x

• 91 and 47, 63 and x

What equation is formed by the cross products in the second example?

• 91x = 63 + 47

• 91x = 63 - 47

• 91x = 63 * 47

• 91x = 63 / 47