How do you use square roots to solve #2(x+3)^2=8#?

2 Answers
Apr 15, 2018

#x=-1,-5#

Explanation:

Our first step would be to divide both sides by #2#. We get:

#(x+3)^2=4#

We can take the #+-# square root of both sides, and we will now have two equations:

The first:
#x+3=2#

#color(blue)(=>x=-1)#

The second:
#x+3=-2#

#color(blue)(=>x=-5)#

We have two equations because we need to take the #+-# square root of both sides, because when you take the sqrt of a number, there will always be a positive and a negative answer.

Hope this helps!

Apr 15, 2018

Express the answer with surds, it's not possible here as the surd is a perfect square.

Explanation:

So

#2(x+3)^2 = 8#

#(x+3)^2 = 4#

#(x+3) = +- sqrt4#
#x = +- 2 - 3#