three consecutive natural numbers are such that the square of the middle number exceeds the difference of the square of the other two by 60 find the numbers
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Answered by
18
Since the middle number of the three consecutive numbers is x, the other two numbers are x -1 and x +1.
According to the given condition, we have
x² = [(x +1)² -(x -1)²] +60
x² = (x² +2x +1) -(x² -2x +1) +60 = 4x +60
x² -4x -60 = 0 => (x -10)(x +6) = 0
x = 10 or -6
Since x is a natural number, we get x = 10
Hence the three numbers are 9, 10, 11
According to the given condition, we have
x² = [(x +1)² -(x -1)²] +60
x² = (x² +2x +1) -(x² -2x +1) +60 = 4x +60
x² -4x -60 = 0 => (x -10)(x +6) = 0
x = 10 or -6
Since x is a natural number, we get x = 10
Hence the three numbers are 9, 10, 11
Answered by
2
Step-by-step explanation:
Let the three consecutive natural numbers be x,x+1, x+2.
Given that Square of the middle number exceeds the difference of the squares of the other two by 60.
(x + 1)^2 = (x + 2)^2 - (x)^2 + 60
x^2 + 1 + 2x = x^2 + 4 + 4x - x^2 + 60
x^2 + 1 + 2x = 4x+ 64
x^2 = 4x + 64 - 2x - 1
x^2 = 2x + 63
x^2 - 2x - 63 = 0
x^2 - 9x + 7x - 63 = 0
x(x - 9) + 7(x - 9) = 0
(x - 9)(x + 7) = 0
x = 9,-7.
x value cannot be -ve, so, x = 9.
Then,
x + 1 = 10
x + 2 = 11.
Therefore the three natural numbers are 9,10,11.
Verification:
(x + 1)^2 - (x + 2)^2 + x^2 = 60
10^2 - 11^2 + 9^2 = 60
100 - 121 + 81 = 60
-21 + 81 = 60
60 = 60.
Hope this helps!
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