1) 3/25 = 9/x3x = 225x = 225/3x = 75
2) 2/19 = 4/y2y = 76y = 76/2y = 38
3) 5/14 = y/425*42 = 14y210 = 14yy = 210/14y = 15
4) a/48 = 7/1212a = 48*712a = 336a = 336/12a = 28
5) 3,2/y = 0,8/1,53,21,5 = 0,8y4,8 = 0,8yy = 4,8/0,8y = 6
6) b/1,6 = 0,07/0,160,16b = 1,6*0,070,16b = 0,112b = 0,112/0,16b = 0,7
7) 20/9 = y/1,81,8*20 = 9y36 = 9yy = 36/9y = 4
8) 25/4 = b/1313*25 = 4b325 = 4bb = 325/4b = 81,25
9) 0,6/1,7 = 0,06/x1,7*0,6 = 0,06x1,02 = 0,06xx = 1,02/0,06x = 17
10) 0,7/1,5 = 2,8/c1,5*0,7 = 2,8c1,05 = 2,8cc = 1,05/2,8c = 0,375
1) 3/25 = 9/x
3x = 225
x = 225/3
x = 75
2) 2/19 = 4/y
2y = 76
y = 76/2
y = 38
3) 5/14 = y/42
5*42 = 14y
210 = 14y
y = 210/14
y = 15
4) a/48 = 7/12
12a = 48*7
12a = 336
a = 336/12
a = 28
5) 3,2/y = 0,8/1,5
3,21,5 = 0,8y
4,8 = 0,8y
y = 4,8/0,8
y = 6
6) b/1,6 = 0,07/0,16
0,16b = 1,6*0,07
0,16b = 0,112
b = 0,112/0,16
b = 0,7
7) 20/9 = y/1,8
1,8*20 = 9y
36 = 9y
y = 36/9
y = 4
8) 25/4 = b/13
13*25 = 4b
325 = 4b
b = 325/4
b = 81,25
9) 0,6/1,7 = 0,06/x
1,7*0,6 = 0,06x
1,02 = 0,06x
x = 1,02/0,06
x = 17
10) 0,7/1,5 = 2,8/c
1,5*0,7 = 2,8c
1,05 = 2,8c
c = 1,05/2,8
c = 0,375