Answer:
Number Operation =
given that the equation we must maintain the similarities. so that :
15 - 2 = 20 - 7
13 = 13
a + 2 = 16 + 3
a + 2 = 19
a = 19 - 2
a = 17
13 - 6 = b - 9
7 = b - 9
7 + 9 = b
b = 16
10 . 6 = 15 . c
60 = 15c
c = 60/15
c = 4
10/d = 20/4
10/d = 5
d = 10/5
d = 2
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