a. ( x + 4 )² = x² + 8x + 16
b. ( 10x - 5 )² = 100x² - 100x + 25
c. ( 2x + 3 )² = 4x² + 12x + 9
d. ( x - 4 ) ( x + 4 ) = x² - 16
e. ( 7x + 1 ) ( 7x - 1 ) = 49x² - 1