Answer: See explanation
Explanation:
The nth term of a geometric progression is calculated by:
= ar^n-1
1). -3,-6,-12,-24 find a10
a = first term = -3
r = common ratio = -6/-3 = 2
n = 10
Using the formula
a10 = ar^n-1
a10 = -3 × 2^10-1
a10 = -3 × 2^9
a10 = -3 × 512
a10 = -1536
2). -2,6,-18,54 find a12
a = first term = -2
r = common ratio = 6/-2 = -3
n = 12
Using the formula
ar^n-1
a12 = -2 × -3^12-1
a12 = -2 × -3^11
a12 = -2 × -177147
a12 = 354294