Question

I would like some help on this please. :)
The attachment is below.

Answer 1

tn = 1-4n

t12 = 1-4*12

t12 = 1-48

t12 = -47

tn =1/2 n+3/2

t12 = 1/2 (12) + 3/2

t12 = 12/2 + 3/2

t12 = 15/2

t12 = 7 1/2

9,4,-1

a1=9

d = 4-9 =-5

an =a1+d(n-1)

-146 = 9 + -5(n-1)

subtract 9 from each side

-155= -5(n-1)

divide by -5

31 = n-1

add 1 to each side

n=32

the 32nd term is -146