bsr qui pourrais m expliquer mon exo 12 merci

bonsoir
a ) 7 x 4/7 = 28/7 = 4
b ) 8 x 11/8 = 88 /8 = 11
c) 9 x 5/9 = 45/9 = 5
d) 14 x 9/14 = 126/14 = 9