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William

10-28-2013, 05:46 PM

Which of the following is the value of a so that the terms 2a-4 , \ a+4, \4a+5 are consecutive terms of an arithmetic sequence?

(A) \frac{3}{4}

(B) \frac{5}{4}

(C) \frac{7}{4}

(D) \frac{9}{4}

Thanks!:D

Thomas

10-28-2013, 05:47 PM

If the terms 2a-4 , \ a+4, \4a+5 are consecutive terms of an arithmetic sequence then

(a+4)- (2a-4)=(4a+5)-(a+4) \Rightarrow a+4-2a+4=4a+5-a-4 \Rightarrow

-a+8=3a+1 \Rightarrow 4a=7 \Rightarrow a=\frac{7}{4}

Therefore the correct answer is (C).

William

10-28-2013, 05:48 PM

Thank you for your kind and quick response Thomas!!;)

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