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1 Answer
Jim G.
Jan 31, 2018

#x=4+-sqrt19#

Explanation:

#"use the method of "color(blue)"completing the square"#

#• " coefficient of "x^2" term must be 1 which it is"#

#• " add/subtract "(1/2"coefficient of x-term")^2" to"#
#x^2-8x#

#x^2+2(-4)xcolor(red)(+16)color(red)(-16)-3#

#rArr(x-4)^2-19=0#

#rArr(x-4)^2=19#

#color(blue)"take square root of both sides"#

#sqrt((x-4)^2)=+-sqrt19larrcolor(blue)"note plus or minus"#

#rArrx-4=+-sqrt19#

#"add 4 to both sides"#

#rArrx=4+-sqrt19#

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