44
The pattern is +1,+1,x2
Step-by-step explanation:
1) -9 = 9 true/false
the answer is false because negative and positive quite unlike in terms.
2) -(-21) = -21
Using the symbols multiplication rule,
Where,
<h2>
+ × + = +</h2><h2>
- × - = +</h2><h2>
- × + = -</h2><h2>
+ × - = -</h2>
Therefore, -(-21) = +21 = 21
⟼ 21 = -21 
Answer:

Step-by-step explanation:

Distribute negative sign.

Combine like terms.


Answer:
12
Step-by-step explanation:
49 - 37 = 12
or
It takes 12 jumps to get from 37 (a) to 49 (c)
Answer: the associative property of addition
Step-by-step explanation: when adding three or more terms, you can combine the middle terms with either the first term or the last term and as you add the results, the sum will be the same either way.