Solving Proportions with Cross Products

This video tutorial by Mr. Backwork explains how to solve proportions using cross products. It covers several examples, including solving proportions with variables in the denominator and applying the distributive property. The tutorial concludes with a word problem involving a scale model, demonstrating how to set up and solve proportions in real-world scenarios.

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

• Multiply the denominators of both fractions

• Subtract the numerators of both fractions

• Add the numerators of both fractions

• Multiply the denominator of one fraction by the numerator of the other

In the first example, what is the value of x when 6x equals 120?

• 25

• 30

• 20

• 15

When using the distributive property in cross products, what must you remember to do?

• Multiply both terms by the same number

• Divide the terms by the same number

• Only multiply the first term

• Add the terms together

What is the result of dividing -18 by -1 in the second example?

• -18

• 18

• 0

• 1

In the third example, what is the simplified form of -6/10?

• -3/10

• -1/5

• -2/5

• -3/5

What is the first step in solving the proportion 4w/(w-3) = 2/3?

• Multiply 4w by 3

• Add 3 to both sides

• Subtract 2 from both sides

• Divide both sides by 4

In the fourth example, why is it beneficial to move the smaller variable first?

• To avoid negative numbers

• To avoid fractions

• To make the equation longer

• To increase the complexity

What is the value of n when -12 - 20 equals -32?

• -12

• -20

• -32

• 0

In the word problem, what is the proportion set up to find the height of the actual building?

• 15/2 = x/14.5

• 15/2 = 14.5/x

• 2/15 = x/14.5

• 2/15 = 14.5/x

What is the height of the actual office building in the word problem?

• 108.75 feet

• 110 feet

• 109 feet

• 108.5 feet