The system
-6x + 6y = 4
-18x + ky = 16
has a unique solution if k is not equal to 18.
x = ?
y = ?
The system has a unique solution if?
2014-09-18 10:49 am
回答 (2)
2014-09-18 11:13 am
Putting which value of x?
2014-09-18 11:09 am
From equation 1, y = (4+6x)/6
Putting this value of x in equation 2
-18x + k[(4+6x)/6] = 16
Multiply throughout by 6
-108x + 4k + 6kx = 96 => 6kx - 108x + 4k = 16 => x = (16-4k)/(6k-108) Provided k is not equal to 18 because if k = 18 then the denominator becomes zero which renders the value of x as indeterminable.
Putting this value of x in equation 1 you will get the value of y
Putting this value of x in equation 2
-18x + k[(4+6x)/6] = 16
Multiply throughout by 6
-108x + 4k + 6kx = 96 => 6kx - 108x + 4k = 16 => x = (16-4k)/(6k-108) Provided k is not equal to 18 because if k = 18 then the denominator becomes zero which renders the value of x as indeterminable.
Putting this value of x in equation 1 you will get the value of y
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https://hk.answers.yahoo.com/question/index?qid=20140918024929AAADzLM