( a + b ) 2 = a 2 + 2 a b + b 2 ( a + b ) ( a − b ) = a 2 − b 2 Which of the following is not an example of how either of these two identities could be used to calculate a product of integers? ( 22 ) ( 18 ) = ( 20 + 2 ) ( 20 − 2 ) = 400 − 4 = 396 ( 22 ) ( 18 ) = ( 20 + 2 ) ( 20 − 2 ) = 400 − 4 = 396 ( 34 ) ( 34 ) = ( 30 + 4 ) ( 30 + 4 ) = 900 + 240 + 16 = 1156 ( 34 ) ( 34 ) = ( 30 + 4 ) ( 30 + 4 ) = 900 + 240 + 16 = 1156 ( 18 ) ( 15 ) = ( 10 + 8 ) ( 10 + 5 ) = 100 + 50 + 80 + 40 = 270 ( 18 ) ( 15 ) = ( 10 + 8 ) ( 10 + 5 ) = 100 + 50 + 80 + 40 = 270 ( 205 ) ( 195 ) = ( 200 + 5 ) ( 200 − 5 ) = 40 , 000 − 25 = 39 , 975 ( 205 ) ( 195 ) = ( 200 + 5 ) ( 200 − 5 ) = 40 , 000 − 25 = 39 , 975