How do you solve #-5sqrt(8x-4) +3 = 18#?

1 Answer
Oct 20, 2015

Answer:

#x in O/#

Explanation:

The idea when dealing with radical equations is to start by isolating the radical term on one side of the equation.

In your case, you can do that by adding #-3# to both sides of the equation and dividing all the terms by #-5#.

#-5sqrt(8x-4) + color(red)(cancel(color(black)(3))) - color(red)(cancel(color(black)(3))) = 18 - 3#

#(color(red)(cancel(color(black)(-5))) sqrt(8x-4))/(color(red)(cancel(color(black)((-5))))) = 15/((-5))#

#sqrt(8x - 4) = -3#

Notice that you have the square root returning a negative value. This cannot happen when dealing with real numbers because you can only take the square root of positive numbers and you will always get a positive number as a result.

This means that the original equation has no real solutions, or #x in O/#.