One root of 3x^2 - 2(3b + 1)x + 4b = 0 is 8. Find the value of b.?
回答 (3)
2018-10-24 6:03 pm
Just substitute x = 8. It will leave an equation in b.
3*(8^2) - (6b + 2)*8 + 4b = 176 - 44b = 0
b = 4
3*(8^2) - (6b + 2)*8 + 4b = 176 - 44b = 0
b = 4
2018-10-24 4:31 pm
192 - 16 [ 3b + 1 ] + 4b = 0
192 - 48 b - 16 + 4b = 0
176 = 44 b
b = 4
192 - 48 b - 16 + 4b = 0
176 = 44 b
b = 4
2018-10-24 7:47 pm
3x² - 2x.(3b + 1) + 4b = 0 → given that one of the root is 8
3.(8)² - 2.(8).(3b + 1) + 4b = 0
192 - 48b - 16 + 4b = 0
176 - 44b = 0
44b = 176
b = 4
3.(8)² - 2.(8).(3b + 1) + 4b = 0
192 - 48b - 16 + 4b = 0
176 - 44b = 0
44b = 176
b = 4
收錄日期: 2021-04-24 07:29:03
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https://hk.answers.yahoo.com/question/index?qid=20181024074847AAPNcin