A positive number when decreased by 4 is equal to 21 times the reciprocal of the number. The number is?
- 7
- 8
- 9
- None of these
Explanation
Given equation:
x - 4 = 21(1/x)
Multiply both sides by x:
x² - 4x = 21
Rearrange the equation:
x² - 4x - 21 = 0
Factor the quadratic equation:
(x - 7)(x + 3) = 0
Solve for x:
x = 7 (since x is a positive number)
Related MCQs
- -72
- -60
- -48
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
- {1}
- {-1}
- {0}
- None of these
اس سوال کو وضاحت کے ساتھ پڑھیں
