F.4 A.MATHS 高手請進

let x and y be the roots of(a)x^2+(b)X+C=0

because x+y=-(b/a)
xy=c/a

so the answer of (1)is 兩根之和=-1/6
兩根之積=-(5/36)
9 - 2x - 7x^2 = 0
-7x^2-2x+9=0
so the answer of (2)is 兩根之和=-(2/7)
兩根之積=-(9/7)

1 36x²+6x-5=0
兩根之和=-6/36 =-1/6

兩根之積=-5/36

2 9 - 2x - 7x² = 0
-7x²-2x+9=0
兩根之和=-2/7
兩根之積=-9/7

1.和=－1/6
積=－5/36
2和=－2/7
積=－9/7

1. 兩根之和=-b/a=-6/36=-1/6
兩根之積=c/a=-5/36

2. 兩根之和=-b/a=-(-2)/(-7)=-2/7
兩根之積=c/a=9/(-7)=-9/7

α＋β＝ -1/6
αβ＝ -5/36
2.α＋β＝ 2/7
αβ＝9/7