Exercise 3 Page 30

We want to find the difference. Let's look at the given expression! 4- 5 12 We can recall that subtracting a number is the same as adding its opposite. 4- 5 12 ⇔ 4+(- 5 12) Before we can evaluate our sum involving mixed numbers, we can rewrite - 5 12 as a decimal. 4+(- 5 12) ⇔ 4+(- 5.5) Now, we can find the sum of two numbers with different signs. We can do so by subtracting the lesser absolute value from the greater absolute value. Then, we will use the sign of the number with the greater absolute value. First, we can calculate the absolute value of the numbers. | 4|=4and| - 5.5|=5.5 Notice that |- 5.5| is greater than | 4|. This means that we should subtract | 4| from |- 5|. Let's do it!

|- 5.5 |-|4|

SubstituteValues

Substitute values

5.5-4

SubTerm

Subtract term

1.5

Recall that the number with the greater absolute value has a negative sign. This means that our difference is a negative number, - 1.5.