How do you solve #2x^2-116= - x ^ { 2} + 247#?

1 Answer
Dec 14, 2017

#x=+-11#

Explanation:

#"add "x^2" to both sides"#

#2x^2+x^2-116=cancel(-x^2)cancel(+x^2)+247#

#rArr3x^2-116=247#

#"add 116 to both sides"#

#3x^2cancel(-116)cancel(+116)=247+116#

#rArr3x^2=363#

#"divide both sides by 3"#

#(cancel(3) x^2)/cancel(3)=363/3#

#rArrx^2=121#

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

#sqrt(x^2)=+-sqrt121larrcolor(blue)"note plus or minus"#

#rArrx=+-11#