Question

The first four terms of a sequence are shown below. -10, -14, -18, -22 Which explicit formula can be used to determine the nth term in the sequence?

Answer 1

-10, -14 , -18, -22

The correct formula is a(n) = -4n - 6.

When n= 1 , a ( 1 ) = -4( 1) - 6 = - 4 -6 = -10,

When n= 2, , a (2) = -4 ( 2) - 6 = -8 - 6 = -14,

When n = 3, a ( 3) = - 4( 3) -6 = -12 - 6 = -18,

When n n = 4, a( 4) = -4 (4) -6 = -16 -6 = -22.