-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:
2x-6
Step-by-step explanation:
Answer:

Step-by-step explanation:
The diagonal of any square with side length
is equal to
. Since the side length of the square is 10, the diagonal must be
.
To support and prove this:
The diagonal creates two 45-45-90 triangles, with the diagonal being the hypotenuse of both of these triangles. The Pythagorean Theorem states that in any triangle, the sum of the squares of both legs is equal to the square of the hypotenuse (
).
Call the diagonal
. In these two triangles, both legs are equal to 10 (the side lengths of the square), and the hypotenuse is the diagonal. Thus, we have:

Answer:B
Step-by-step explanation:
Just did it on math nation