Exploring Rational Expressions: Adding and Subtracting Techniques

The video tutorial covers lesson 9.8, focusing on reviewing proportional graphs and solving problems using proportions. The teacher revisits the concept of proportionality, emphasizing that a graph is proportional if it is a straight line through the origin. Students practice identifying proportional graphs. The tutorial then demonstrates setting up proportions to solve real-world problems, including predicting sales, emoji usage, defective products, and probability calculations. The teacher provides step-by-step solutions and encourages students to follow along in their note packets.

What is the key characteristic of a proportional graph?

• It is a straight line that passes through the origin.

• It is a curved line that does not pass through the origin.

• It is a curved line that passes through the origin.

• It is a straight line that does not pass through the origin.

Is a graph that is a straight line but does not pass through the origin proportional?

• Yes

• No

• Sometimes

• Depends on the slope

If a graph passes through the origin but is not a straight line, is it proportional?

• No

• Depends on the context

• Yes

• Sometimes

How many pairs of jeans should be ordered if 25 out of 50 surveyed customers prefer jeans and 450 pairs are to be ordered?

• 275

• 225

• 250

• 200

What percentage of people use emojis if 15% do not use them?

• 75%

• 80%

• 85%

• 90%

How many students at Washington Middle School use emojis if 85% of 2450 students use them?

• 2100

• 2000

• 2200

• 2082

What is the decimal equivalent of 2.5%?

• 0.00025

• 0.0025

• 0.25

• 0.025

How many defective light bulbs are estimated if 2.5% of 14,500 light bulbs are defective?

• 360

• 362

• 363

• 365

What is the probability that a student brought a photo taken at a theme park if 11 out of 28 students did?

• 11/28

• 10/28

• 9/28

• 12/28

How many students at Mr. Blackwell's school would bring in a theme park photo if 11 out of 28 students in his class did and there are 560 students in total?

• 210

• 200

• 240

• 220