kerjakan di atas dengan benar

a) u101 = a + (n-1)b
u101 = 3 + (101-1) 7
u101= 3 + 100.7
u101 = 3 + 700
= 703
b) u15 = a + (n-1) b
135 = 9 + (15-1) b
135 = 9 + 14 b
135-9 = 14b
126 = 14b
b = 126/14
b = 9
c) u21 =a +(n-1) b
336 = a +(21-1) 17
336 = a + 20.17
336 = a + 340
336-340 = a
-6 = a atau a = -6
d) u26 = a +( n-1) b
-65 = 110 + (26-1) b
-65 = 110 + 25b
-65-110= 25b
-175 = 25 b
-175/25 = b
-7 = b atau b = -7
e) un = a + (n-1) b
-99 = 21 +(n-1) -8
-99= 21 + (-8n+8)
-99 = 21 +8 -8n
-99 = 29-8n
-99-29 = -8n
-128 = -8n
-128/-8 = n
16 = n, jadi n= 16