Answer:
- using the rule given: 2.5
- using an exponential rule: 7
Step-by-step explanation:
Evaluating the linear rule given, for n = 1, we have ...
a1 = 7(1/2)(1) -1 = 7/2 -1 = 5/2 = 2.5
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We suspect you may intend the exponential function ...
an = 7(1/2)^(n-1)
Then, for n = 1, we have ...
a1 = 7(1/2)^(1 -1) = 7(1) = 7 . . . . the first term is 7
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When writing an exponential expression in plain text, it requires the exponential operator, a caret (^). If the exponent contains any arithmetic, as this one does, it must be enclosed in parentheses.
The anwser to your problem is 1,800
First you'll need to get the same denominator. So instead of 3/5 and 3/8 you'll have 24/40 and 15/40. Now that we've changed the value of the denominator, the 40/40 will now represents the 1 hour that Jenny has before bedtime. So you add 24/40 and 15/40 and get 39/40. 39/40 stands for the time that Jenny has already spent brushing her teeth and texting her friend all together. Since the 1 hour is 40/40 subtract 39/40 from it to get 1/40. 1/40 is equal to the rest of the time Jenny spends reading or 1.5 minutes.
