7. Find three numbers in A.P.
whose sum is 21 and their
product is 231.
Answers
Answered by
7
Let the AP is (a−d),a,(a+d)
(a−d),a,(a+d) =21
3a=21
a=7
(a−d)×a×(a+d)=231
(a×a−d×d)×a=231
(7×7−d×d)×7=231
(7×7−d×d)=
7
231
(7×7−d×d)=33
d×d=49−33
d×d=16
d=4
Hence, the A.P is 3,7,11
I hope it will helpfull....☺️
Answered by
2
Let the AP is (a−d),a,(a+d)
(a−d),a,(a+d) =21
3a=21
a=7
(a−d)×a×(a+d)=231
(a×a−d×d)×a=231
(7×7−d×d)×7=231
(7×7−d×d)=
7
231
(7×7−d×d)=33
d×d=49−33
d×d=16
d=4
Hence, the A.P is 3,7,11
I hope it will helpfull....
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