(a) Expand and simplify (a×a) – (a - b)(a + b). (b) Hence write down the value of
(6730×6730) – 6728 x 6732 without using a
calculator.​

Which of the following is not a challenge to instituting sound global environmental policies? a. most changes are inexpensive and easy to implement. b. elected leaders who support unpopular environmental issues often are not re-elected. c. economic considerations outweigh environmental ones in many societies. d. there is no way to enforce international environmental agreements.

In the construction of new housing development, which factor of production can be categorized as land?

Which of the following best describes the purpose of a nation’s boundaries? a. to limit the movement of goods and people b. to make it easier for cartographers to create maps c. to make the movement of goods and people easier d. to prevent other countries from invading territory