(8а-3)×(8а+3)-(7а+4)×(8а-4)

Question

(8а-3)×(8а+3)-(7а+4)×(8а-4)

Answer 1

(8a - 3)(8a + 3) - (7a + 4)(8a - 4) = 64a² - 9 - (56a² - 28a + 32a - 16) = 64a² - 9 - 56a² + 28a - 32a + 16 = 8a² - 4a + 7