1.Consider f(x)=x^2 - 3x +1 and g(x) = 7+2x.Find the values of x such that f(x+1) = g(3x)
2.If h(x) = 7x^2 - 10x -12 and k(x) = -(5/3)x , find the values of x such that h(x) = k(7x+6)
F.4 quadratic equations
2009-10-22 3:31 am
回答 (1)
2009-10-22 3:47 am
✔ 最佳答案
1.f(x+1)=(x+1)^2-3(x+1)+1g(3x)=7+2(3x)
(x+1)^2-3(x+1)+1=7+2(3x)
x^2+2x+1-3x-3+1=7+6x
x^2-x-1=7+6x
x^2-7x-8=0
(u 果條公式)
x=8 or -1
2.k(7x+6)=-(5/3)(7x+6)
7x^2-10x-12=-(5/3)(7x+6)
7x^2-10x-12=-35/3x-10
21x^2-30x-36=-35x-30
21x^2+5x-6=0
x=3/7 or -2/3
參考: me
收錄日期: 2021-04-22 23:34:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091021000051KK01068