Answer:
an = 6n - 18
Step-by-step explanation:
a3 = 0, a4 = 6, a5 = 12, a6 = 18, a7 = 24
a3 = a + 2d
a4 = a + 3d
a + 2d = 0 (1)
a + 3d = 6 (2)
Subtract (1) from (2) to eliminate a
3d - 2d = 6 - 0
d = 6
Substitute d = 6 into (1)
a + 2d = 0 (1)
a + 2(6) = 0
a + 12 = 0
a = -12
nth term,an = a + (n - 1)d
= -12 + (n - 1) 6
= -12 + 6n - 6
= 6n - 18
an = 6n - 18
