How do you solve: #3x^2 - 5 = 0#?

1 Answer
Jan 28, 2017

See the entire solution process below:

Explanation:

First, add #color(red)(5)# to each side of the equation to isolate the #x# term while keeping the equation balanced:

#3x^2 - 5 + color(red)(5) = 0 + color(red)(5)#

#3x^2 - 0 = 5#

#3x^2 = 5#

Next, divided each side of the equation by #color(red)(3)# to isolate the #x^2# term while keeping the equation balanced:

#(3x^2)/color(red)(3) = 5/color(red)(3)#

#(color(red)(cancel(color(black)(3)))x^2)/cancel(color(red)(3)) = 5/3#

#x^2 = 5/3#

Now, take the square root of each side of the equation to solve for #x# while keeping the equation balanced. Remember the square root produces a positive and negative answer for the solution:

#sqrt(x^2) = +-sqrt(5/3)#

#x = +-sqrt(5/3) = +-1.291# rounded to the nearest thousandth.