Question

7/28 = х/12 14/10=21/х

Answer 1

7/28 = х/12
х= 7*12: 28
х= 3
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14/10 = 21/х
х=10*21:14
х= 15

Answer 2

45/25=18/х

Answer 3

х= 25*18 : 45, х= 10

Answer 4

;-)