51: 51, 102, 153, 204, 255.
52: 52, 104, 156, 208, 260.
They are 52*1, 52*2, 52*3, 52*4 and 52*5.
13, 26, 39, 52, 65
13, 26, 39, 52, 65
13, 26, 39, 52, 65
26, 52, 78, 104, 130.
That depends on where you start and in which direction you explore. For example,if you start at 999 and examine the numbers as you count downward, then the firstfive multiples of 51 that you should encounter would be 969, 918, 867, 816, and 765.
The first 5 multiples of 17 are: 17, 34, 51, 68, and 85.
All the multiples of 5 between 1 and 51 are: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 These add up to 275.
They are the first three multiples of LCM(5, 9), that is, the first three multiples of 45.
The first 5 common multiples are the first 5 multiples of their lowest common multiple (LCM) LCM(9, 10) = 90 → first 5 common multiples are 90, 180, 270, 360, 450.
13 26 39 52 65
-13, -26, -39, -52, -65.