Answer:
D. (-9)+9=0
Step-by-step explanation:
Additive inverse means that the sum of the original number and its Additive inverse must add upto 0. In this case, if we add -9 and 9 then we get 0. That's why D is the correct answer.
The number of observations is 15
Answer:
$138
Step-by-step explanation:
We can first turn the words into a mathematical equation by substituting words with the information we have:
Total earning - ( Price of three books)
$180 - (Price of one book x 3)
$180 - ($14 x 3)
Finally, after we have created the mathematical equation, we solve it!
$180 - ($14 x 3)
$180 - $42
$138