First, subtract #color(red)(30)# from each side of the equation to isolate the #x# term while keeping the equation balanced:
#- color(red)(30) - 19 = - color(red)(30) + 30 - 7x^2#
#-49 = 0 - 7x^2#
#-49 = -7x^2#
Next, divide each side of the equation by #color(red)(-7)# to solve for #x^2# while keeping the equation balanced:
#(-49)/color(red)(-7) = (-7x^2)/color(red)(-7)#
#7 = (color(red)(cancel(color(black)(-7)))x^2)/cancel(color(red)(-7))#
#7 = x^2#
#x^2 = 7#
Now, take the square root of each side of the equation to solve for #x# while keeping the equation balanced. Remember, the square root of the number yields both a positive and a negative result:
#sqrt(x^2) = +-sqrt(7)#
#x = +-sqrt(7) = 2.646# rounded to the nearest thousandth.
