How do you solve #x^2+8x-10=0# by completing the square?

1 Answer
Jim G.
Mar 19, 2018

#x=-4+-sqrt26#

Explanation:

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

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

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

#x^2+2(4)xcolor(red)(+16)color(red)(-16)-10=0#

#rArr(x+4)^2-26=0#

#rArr(x+4)^2=26#

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

#rArrx+4=+-sqrt26larrcolor(blue)"note plus or minus"#

#"subtract 4 from both sides"#

#rArrx=-4+-sqrt26larrcolor(red)"exact solutions"#

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