-2-(+7) is the same thing at -2-7 which is -9

is the same thing as

which is

or

Last but not least the last one is the Associative Property based on definition listed below :)
Associative Property:<span> When three or more numbers are added, the sum is the same regardless of the grouping of the addends. For example (2 + 3) + 4 = 2 + (3 + 4)</span>
Answer: The quick way is to square the half of it.
Step-by-step explanation: You divide your main number by 2 and figure out that half. If it is still too big, divide by 2 again. If you need to keep repeating that is fine. Thank you multiply your answer by however many times you divided by 2.
Answer:
The number he thought of was 13
Step-by-step explanation:
Revers the problem
3.5 * 3 = 10.5
10.5 - 4 = 6.5
6.5 * 2 = 13
Answer: Ms. Taylor earns $1400 a month (good for her)
Step-by-step explanation:
420/3 = $140
$140 x 10 = 1400