First, add #color(red)(5)# to each side of the equation to isolate the #x# term while keeping the equation balanced:
#9x^2 - 5 + color(red)(5) = 121 + color(red)(5)#
#9x^2 - 0 = 126#
#9x^2 = 126#
Next, divide each side of the equation by #color(red)(9)# to isolate the #x^2# term while keeping the equation balanced:
#(9x^2)/color(red)(9) = 126/color(red)(9)#
#(color(red)(cancel(color(black)(9)))x^2)/cancel(color(red)(9)) = 14#
#x^2 = 14#
Now, take the square root of each side of the equation to solve for #x# while keeping the equation balanced. Remembering, the square root of a number can be either #+# or #-# the number:
#sqrt(x^2) = +-sqrt(14)#
#x = +-sqrt(14) = +-3.74# rounded to the nearest hundredth.
