Answer:
-84
Step-by-step explanation:
The formula for the nth term of a geometric progression is
Un = ar^n- 1
The sum of the first six terms of a geometric series (U6) = 21/16
Common ratio = -1/2 ,
a = First term ??
21/16 = a × (-1/2 )^6- 1
21/16 = a ×(-2^-1)^5
21/16 = a × -2^-6
Cross Multiply
16 × a × -2^-6 = 21
a = 21/16 × -2^-6
a = 21/16 ×- 1/2⁶
a = 21/16 × -1/64
a = 21 ÷(-1/4)
a = 21 × -4
a = -84
The first term = 84
is it 42 or 4 and 2 separate
Answer:
A8 = 66 [8th term]
Step-by-step explanation:
Given the explicit arithmetic sequence An = -14 + 10n → -4 + 10(n-1)
To find the 8th term. An nth term is where n is n in the sequence. So substitute 8 for n, and simplify.
So A8 = -4 + 10(8-1) → -4 + 10(7) → -4 + 70 → 70 - 4 → 66.
In percentage form it is 83.33% repeating, but in dollars it is $50
