Math, asked by vignesh090803p2sta4, 1 year ago

the sum of four consecutive numbers in an ap is 32 and the ratio of the product of the first and the last term to the product of two middle term is 715 find the numbers.​

Answers

Answered by Potenz
2

Hey there!

Here is your answer

Let the AP with 4 terms be:

a-3d, a-d, a+d, a+3d------------(1)

Given, S4=32;

a-3d+a-d+a+d+a+3d=32

4a=32

=a=32/4= 8

Product of first and last term/product of the 2 middle terms= 7/15

(a-3d)(a+3d)/(a-d)(a+d)=7/15

a^2-9d^2/a^2-d^2)=7/15

15(a^2-9d^2)=7(a^-d^2)

=15a^2-135d^2=7a^2-7d^2

=15a^2-7a^2= 135d^2-7d^2

=8a^2=128d^2

(a=8)

==> 8(8)^2/128=d^2

=512/128=d^2

=d^2=4

=d= +/-2

Substitute the values of a and d in (1)

And there by AP=

2,6,10,14/ 14,10,6,2

____________________________

Hope it helps you!!

Happy learning ✨


vignesh090803p2sta4: but why a-3,a-d...?
Potenz: That's how it should be.. as far as I know :) ..similarly for 3 terms,the consecutive terms has to be in the form: a-d,a,a+d. And for 5 terms :a-2d,a-d,a+d,a+2d
vignesh090803p2sta4: ok thanks
Potenz: It's okay! :)
Answered by Anonymous
0

plz refer to this attachment

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