If a and B are the roots of the equation x^2 - 5x + 5 = 0, find the values of
a^2 + 5B + 5
Ans: 25. Steps?
F4 Maths
2011-09-25 5:37 pm
回答 (1)
2011-09-25 6:07 pm
✔ 最佳答案
a^2 - 5a + 5 = 0so a^2 = 5a - 5
so a^2 + 5b = 5 = 5a - 5 + 5b + 5 = 5(a + b)
Sum of roots = a + b = 5
so 5(a + b) + 10 = 5(5) = 25.
2011-09-25 10:09:47 補充：
Correction : Last line should be simply 5(a + b), disregard the +10, sorry. 3rd line should be " so a^2 + 5b + 5 = .........".
收錄日期: 2021-04-25 22:38:38
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https://hk.answers.yahoo.com/question/index?qid=20110925000051KK00184