# Pre-Calc/Trig

posted by Sheila

What are the roots of the equation x^2 - 4x + 3 = 0

I think I was suppose to use b^2 - 4ac
so it would be -4 - (-4)*1*3 = 12 so the roots would be 12 and -12

1. Sheila

x^2 -4x + 3 = 0
x^2 - 4x = 3
x^2 +2(-2)x + -2^2 = -3 = -2^2
x^2 + -4x + 4 = 1
(x + -2)^2 = 1
qrt (x+-2)^2 = sqrt 1
x+-2 = plus or minus 1
therefore x=1
x=3 roots are 1 and 3

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