The sum of a number and its reciprocal is 4.25 .Find the number?Please also give me steps for solving it
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Answered by
34
Let the number be x,
x +1/x = 4.25
(x² +1)/x = 4.25
x²+1 = 4.25*x
Multiply by 4 on both sides
4x² +4 = 17x
4x² -17x +4 =0
4x² -(16+1)x +4 =0
4x² -16x -x +4 =0
4x(x-4) -1(x-4) =0
(4x-1)(x-4) =0
4x-1 =0 OR x-4 =0
4x =1 Or x=4
x =1/4 Or x=4
Now, the number is 4 OR 1/4
If we take 4, its reciprocal will 1/4
If we take 1/4, its reciprocal will be 4
In both the conditions,
Numbers are 4 and 1/4
So, take any from 4 and 1/4, both will give the same requirements
MAIN ANSWER = 4 as well as 1/4
I hope this will help you
-by ABHAY
x +1/x = 4.25
(x² +1)/x = 4.25
x²+1 = 4.25*x
Multiply by 4 on both sides
4x² +4 = 17x
4x² -17x +4 =0
4x² -(16+1)x +4 =0
4x² -16x -x +4 =0
4x(x-4) -1(x-4) =0
(4x-1)(x-4) =0
4x-1 =0 OR x-4 =0
4x =1 Or x=4
x =1/4 Or x=4
Now, the number is 4 OR 1/4
If we take 4, its reciprocal will 1/4
If we take 1/4, its reciprocal will be 4
In both the conditions,
Numbers are 4 and 1/4
So, take any from 4 and 1/4, both will give the same requirements
MAIN ANSWER = 4 as well as 1/4
I hope this will help you
-by ABHAY
abhi569:
Please say thanks
Answered by
2
Answer:
the answer is 4 or 1/4 for x
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