1. d=9-5
d=4
2.a₁₅=5+4*14=69
a₄₇= 5+4*46=189
An=5+4*(n-1)
144/9 = 16/1 = 16
17/5 = 3 2/5
306/10 = 30 6/10 = 30 3/5
101/101 = 1
1) 51 : 17 = 3 (1 \%)