Find the four terms between 15 and 87 in the arithmetic sequence

Answer 1

15, 15+d, 15+2d, 15+3d, 15+4d, 87
87 - (15+4d) = d
72 - 4d = d
5d = 72
d = 72/5 = 14.4

15, 29.4, 43.8, 58.2, 72.6, 87