幾條f.4數唔識做

要有步驟..........................


8. If the product of the roots of the quadratic equation(k+1)x^2 - 10x + k -1=0 is 2 ,where k ≠ -1
a)find the value of k
b)the sum of the roots.


10.If one root of x^2-6x+k=0 is 2, find the other root and the value of k.


11.If α and β are the roots of the equation x^2+x-9+0,find the value of
a)α + β
b)αβ
c)(a+1)(β+1)
d)α ^2+ β^2


12.If α and β are the roots of the equation x^2+2x-6=0,find the values of
a) 1⊥α + 1⊥β ⊥←分線
b)a^2β+aβ^2
c)(a-2)(β-2)
d)a^2+2β