Answer:
Step-by-step explanation:
Remark
I don't think you need the quadratic formula for this equation. It just factors into (b - 2)(b - 2), but I'll do it because you requested it.
Formula
Givens
a = 1
b = - 4
c = 4
Solution
x = - - 4 +/- sqrt((-4^2) - 4*1*4)
====================
2*1
x = 4 +/- sqrt (16 - 16)
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2
x = 4/2
x = 2
There are 2 roots but both of them are the same. Some teachers say there is only 1 root. I'm in that group.