What are the first five terms of an arithmetic sequence if a 17 = ‒40 and a 28 = ‒73? A. 8, 11, 14, 17, 20 B. 8, 5, 2, ‒1, ‒4 C.
1 answer:
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9514 1404 393
Answer:
-28/45
Step-by-step explanation:
<u>Step 1, the sign</u>
When the fractions have an odd number of minus signs (1, not 0 or 2), the result will be negative. This knowledge lets you ignore the sign while you do the rest of the arithmetic. The appropriate sign is applied to the final numbers.
<u>Step 2, the formula</u>
The ratio (a/b)÷(c/d) is (ad)/(bc). There are several ways you can get there:
⇒ "invert and multiply" or "swap dot"
⇒ "numerators of a common denominator"
⇒ "swapped denominators of a common numerator"
The use of common numerators or common denominators is most often seen when the numerator or denominator of one fraction is a multiple of that in the other fraction. <em>Example</em>: (2/3)÷(1/6) = (4/6)÷(1/6) = 4/1 = 4
<u>Step 3, reduce the result</u>
Any of these fractions is reduced by cancelling common factors from numerator and denominator. Your fractions here don't have any common factors, so there is nothing to cancel.
_____
Your product is ...
(4/9) ÷ (-5/7) = -(4·7)/(9·5) = -28/45
