Answer: The right answer is 2
Step-by-step explanation:
- Write out the expression
T1; a = 0.3 ------------ (I)
T8; ar^7 = 38.4 ------------ (ii)
Substituting for 'a' in the second equation, we have;
0.3r^7 = 38.4
0.3r^7 = 38.4
Divide both sides by 0.3
r^7 = 38.4/0.3
r^7 = 128
r = (128)^1/7
r = 2
N = the number
0.5n - 9 = 4n + 5
(0.5n - 0.5n) - 9 = (4n - 0.5n) + 5
-9 = 3.5n + 5
(-9 - 5) = 3.5n + (5 - 5)
-14 = 3.5n
-14/3.5 = 3.5n/3.5
-4 = n
The number is -4.
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