Answer
A) Yes
B) Yes
C) Yes
D) Yes
Work Step by Step
A) 5| $\ (1 - 9^2)$ = 5| -80, because -80 = 5* {-16} , -16 $\in$ Z
B) 5 | $\ (2^2 - 13^2)$ = 5 | -165, because -165 = 5*{-33}, -33 $\in$ Z
C ) 5| $\ (2^2 - 8^2) $ = 5 | -60, because -60 = 5*{-12}, -12 $\in$ Z
D) 5| $\ (8^2 - 2^2) $ = 5 | 60, because 60 = 5*{12}, 12 $\in$ Z
