Find an equation for the nth term of the arithmetic sequence.

a15 = -53, a16 = -5

a) an = -725 - 48(n - 1)
b) an = -725 + 48(n + 1)
c) an = -725 + 48(n - 1)
d) an = -725 - 48(n + 1)

An=a1+d(n-1)

every term increases by d amount

so
therefor


-53+d=-5
add 53 both sides
d=48

alright
an=a1+d(n-1)
an=a1+48(n-1)
use a15=-53
a15=-53=a1+48(15-1)
-53=a1+48(14)
-53=a1+672
minus 672 both sides
-725=a1

the equation is
an=-725+48(n-1)
answer is C