Question

Please help me answer these!!! Thanks :)

Answer 1

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

$-3 \frac{2}{7} -(- \frac{5}{7} )$ is the same thing as $(-3 \frac{2}{7}) + (\frac{5}{7})$ which is $- \frac{18}{7}$ or $-2 \frac{4}{7}$

Last but not least the last one is the Associative Property based on definition listed below :)
Associative Property: 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)