I need help. With this p

Mathematics

1 answer:

iogann1982 [59]3 years ago

6 0

$a_n=a_1+(n-1)d$ - the formula of n-th term of an arithmetic sequence.

We have:

$a_5=12.4;\ a_9=22.4$

$a_9-a_5=(9-5)d\to4d=22.4-12.4\\\\4d=10\ \ \ \ |:4\\\\d=2.5$

$a_{31}=a_9+(31-9)d\to a_{31}=22.4+22\cdot2.5=77.4$

Answer: C. 77.4

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Explanation:
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Given: (x – 3)² = 0 ; write as: general form: "ax² + bx + c = 0"; a ≠ 0 .

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Rewrite: (x – 3)² = 0 ; →
as: x² – 6x + 9 = 0 ; which is our answer.
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→ x² – 6x + 9 = 0 ; is in "general form", or "standard equation format"; that is: " ax² + bx + c = 0 "; (a ≠ 0) ;
→ in which:
a = 1 (implied coefficient, since anything multiplied by "1" is that same value);
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