Percent Increase and Decrease Concepts

This video tutorial covers percent increase and decrease using equations. It begins with an introduction to the concepts, followed by a detailed example of percent increase using a tape diagram and equations. The tutorial then applies these concepts to an investment problem, demonstrating how to calculate the initial amount after a 15% increase. Finally, it explains percent decrease with another example, using a tape diagram to illustrate the concept and showing different ways to write the corresponding equations.

What is the main focus of the lesson in Unit 4, Lesson 8?

• Exploring geometric shapes

• Learning about percent increase and decrease using equations

• Studying historical events

• Understanding fractions and decimals

In the example of percent increase, if y is 15% more than x, which equation correctly represents this relationship?

• y = 1.15x

• y = 0.85x

• y = x + 0.15

• y = x - 0.15x

How can the equation y = x + 0.15x be simplified using the distributive property?

• y = 0.85x

• y = x + 0.15

• y = x - 0.15x

• y = 1.15x

If an investment increases by 15% to $1250, what equation would you use to find the initial amount?

• 1.15x = 1250

• x = 1250 + 1.15

• x = 1250 - 1.15

• x = 1250 / 1.15

What is the initial investment amount if the final value is $1250 after a 15% increase?

• $1,000.00

• $1,250.00

• $1,086.96

• $1,150.00

In the example of percent decrease, if a is 7% less than b, which equation correctly represents this relationship?

• a = b - 0.93b

• a = 0.93b

• a = b + 0.07b

• a = 1.07b

How can the equation a = b - 0.07b be simplified using the distributive property?

• a = 0.93b

• a = b + 0.07b

• a = 1.07b

• a = b - 0.93b

What does the unshaded section in the tape diagram represent when a is 7% less than b?

• 0.07 of b

• 0.93 of b

• 1.07 of b

• 1.00 of b

Which of the following is NOT a way to express a as 7% less than b?

• a = (1 - 0.07)b

• a = b + 0.07b

• a = 0.93b

• a = b - 0.07b

What is the result of subtracting 0.07 from 1 in the context of percent decrease?

• 0.07

• 0.93

• 1.07

• 0.00