Exercise 4 Page 28

We want to find what is the expected temperature. We can use a number line to visualize the given situation. From the exercise, we know that when Preston got home, it was 12^(∘)C. The weather report shows that because of a storm, the temperature will drop by 17^(∘)C. Let's list the steps we will follow to create a number line for this situation.

• First, we start at 0.
• Then, we move 12 units to the right. This represents the temperature when Preston got home.
• Finally, we move 17 units to the left to represent the expected temperature drop.

As we can see from the graph, subtracting 17 from 12 is the same as adding 12 and -17. This is because -17 is the opposite of 17, and subtracting a number is equal to adding its opposite. Let's add the two integers to find the expected temperature. Consider the expression that represents this situation. 12-17=12+(-17) Notice that we are adding two integers with different signs, one positive and one negative. This means that we will subtract the absolute values of the integers. Let's take a look!

|12|-|-17|

AbsPos

|12|=12

12-|-17|

AbsNeg

|-17|=17

12-17

SubTerm

Subtract term

-5

Keep in mind that we moved a greater distance to the left than to the right because |-17| is greater than |12|. That means the result is negative. We can say that the expected temperature is -5^(∘)C.