Question 66212
Using the quadratic equation y = x2 - 6x + 8 = 0, perform the following tasks:
(1)  Solve by factoring.
(2)  Solve by using the quadratic formula. 


(1)  This quadratic equation is in standard form (ax^2+bx+c=0) with:
a=1
b=-6
c=8

Now when a=1, then b is the sum of the factors of c, if the quadratic is factorable. What are the factors of 8 that will add up to -6?????
Well, it's (-4)(-2)

So x^2 - 6x + 8=0 equals
(x-4)(x-2)=0    you can multiply this out to verify
x=4
x=2

(2)

Quadratic formula:  x=(-b+or-sqrt(b^2-4ac))/2a

x=(6+or-sqrt(36-32))/2
x=(6+or-sqrt4)/2
x=-(6+or-2)/2   divide top and bottom by 2
x=3+or-1
x=3+1=4
x=3-1=2


Hope this helps---ptaylor