tolong kerjain nomor 1 sampai 3 makasih

1. a/8=15/12
a=(15 x 8)/12
a= 10

b )
6/b = 21/49
(6 x 49)/21= b
b = 14

c )
18/21 = p/28
(18x28) / 21 = p
24 = p

d)
28/49 = 32/q
q = (32 x 49 )/28
q = 32