Exercise 13 Page 21

We want to find the sum and simplify the result of the addition. Let's look at the given expression! - 1 15+( - 3/5) Before we can evaluate our sum involving mixed numbers, the mixed numbers must first be rewritten as fractions.

a bc	a* c+b/c	Simplify
- 1 15	-(1* 5+1/5)	-6/5

When adding or subtracting fractions they should have the same denominator. In this case, we have two fractions with the same denominator. - 1 15+ 3/4 [0.3em] ⇓ [0.3em] -6/5+( - 3/5) Now, we can find the sum of two fractions with the same sign. Recall that we can do so by adding their absolute values. Let's do it!

|- 6/5|+|- 3/5|

AbsNeg

|-6/5|=6/5

6/5+|- 3/5|

AbsNeg

|-3/5|=3/5

6/5+3/5

AddFrac

Add fractions

6+3/5

AddTerms

Add terms

9/5

FracToMixed

Write fraction as a mixed number

1 45

WriteDec

Write as a decimal

1.8

Recall that both numbers are negative. This means that the sum is also a negative number, - 1 45 or - 1.8.