The difference between the reciprocals of two consecutive numbers is 1/20. Wt are the two numbers?
1. I dunno wt the meaning of reciprocals is
2. I wanna know how 2 solve this question
Thx
Quadratic equations
2006-10-15 3:43 am
回答 (3)
2006-10-15 3:58 am
✔ 最佳答案
The reciprocal of a number x is 1 / x.Example: The reciprocal of 2 is 1 / 2. The reciprocal of 3 is 1 / 3.
Let the smaller number be x. Then the larger number is (x + 1).
1 / x - 1 / (x + 1) = 1 / 20
[x + 1 - x] / [x(x + 1)] = 1 / 20
1 / (x^2 + x) = 1 / 20
x^2 + x = 20
x^2 + x - 20 = 0
(x + 5)(x - 4) = 0
x = -5 or x = 4.
When x = -5, the two numbers are -5 and -4
When x = 4, the two numbers are 4 and 5
2006-10-15 4:16 am
The reciprocal of a number x is 1 / x.
Example: The reciprocal of 2 is 1 / 2. The reciprocal of 3 is 1 / 3.
Let the smaller number be x. Then the larger number is (x + 1).
1 / x - 1 / (x + 1) = 1 / 20
[x + 1 - x] / [x(x + 1)] = 1 / 20
1 / (x^2 + x) = 1 / 20
x^2 + x = 20
x^2 + x - 20 = 0
(x + 5)(x - 4) = 0
x = -5 or x = 4.
When x = -5, the two numbers are -5 and -4
When x = 4, the two numbers are 4 and 5
Example: The reciprocal of 2 is 1 / 2. The reciprocal of 3 is 1 / 3.
Let the smaller number be x. Then the larger number is (x + 1).
1 / x - 1 / (x + 1) = 1 / 20
[x + 1 - x] / [x(x + 1)] = 1 / 20
1 / (x^2 + x) = 1 / 20
x^2 + x = 20
x^2 + x - 20 = 0
(x + 5)(x - 4) = 0
x = -5 or x = 4.
When x = -5, the two numbers are -5 and -4
When x = 4, the two numbers are 4 and 5
2006-10-15 3:50 am
reciprocal(adj.)
互相給與的;互惠的;相互的
互相給與的;互惠的;相互的
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