Question 701471: Z*Z-9Z+8=0
Answer by Simnepi(216)   (Show Source):
You can put this solution on YOUR website! to solve quadratic equations the first thing is to look for factor pairs of the constant term, in this case that is +8.
factors of +8 are: (remember either these have to be both positive or both negative numbers because negative multiplied by negative gives a positive answer)
plus/minus 1 and 8:
plus/minus 2 and 4.
Now we look to see if any of those factor pairs can be added to make the coefficient of the x term (that's the number in front of the x) which is -9.
Obviously the factor pair we need are plus/minus 1 and 8 because -1 + -8 = -9
Now we get two brackets and put an x in both and one of the factors in each bracket
Like this
(x-1)(x-8)
making this equal zero means that either one of these brackets could equal zero, that is,
either (x-1)=0 or (x-8)=0
If (x-1)=0 then x = 1
OR
If (x-8)=0 then x = 8
These are the two solutions
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