Which quadratic equation is equivalent to (x - 4)2 - (x - 4) - 6 = 0?
Solution:
(x - 4)2 - (x - 4) - 6 = 0 [Given]
Expanding using the formula (a - b)2 = a2 + b2 - 2ab
x2 + 16 - 8x - x + 4 - 6 = 0
By further calculation
x2 - 9x + 14 = 0
Using the formula
x = [-b ± √(b2 - 4ac)]/2a
Here a = 1, b = -9 and c = 14
Substituting it in the formula
x = [-(-9) ± √((-9)2 - 4 (1) (14))]/2 (1)
x = [9 ± √(81 - 56)]/2
So we get
x = [9 ± √25]/2
x = (9 + 5)/2 = 14/2 = 7
x = (9 - 5)/2 = 4/2 = 2
Therefore, the quadratic equation equivalent to (x - 4)2 - (x - 4) - 6 = 0 is x2 - 9x + 14 = 0.
Which quadratic equation is equivalent to (x - 4)2 - (x - 4) - 6 = 0?
Summary:
The quadratic equation which is equivalent to (x - 4)2 - (x - 4) - 6 = 0 is x2 - 9x + 14 = 0.
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