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 Question from sammantha, a student: Find the 3rd term of the sequence, an=1.5(4)n - 1.

Hi Sammantha,

The letter $n$ in the expression

$a_n = 1.5 \times 4^n - 1$

is the term number. For the first term substitute $n = 1$ into the expression to get

$a_1 = 1.5 \times 4^1 - 1 = 1.5 \times 4 - 1 = 6 - 1 = 5.$

For the second term substitute $n = 2$ into the expression to get

$a_2 = 1.5 \times 4^2 - 1 = 1.5 \times 16 - 1 = 24 - 1 = 23.$

What is the third term?

Penny

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