x : 4 = 9
x = 4 x 9
x = 36
36 : 4 = 9 ✓
49 : x = 7
x = 49 : 7
x= 7
49 : 7 = 7 ✓
6 x X = 24
x = 24 : 6
x = 4
6 x 4 = 24 ✓
81 : x = 9
x = 81 : 9
x = 9
81 : 9 = 9 ✓