How do you solve #2= \frac { 1} { 2} root[ 3] { x - 7} + 3#?

1 Answer
Dec 23, 2016

#x=-1#

Explanation:

First, we begin with #1/2root(3)(x-7)+3=2#. This looks messy, but it is actually pretty simple, as long as we go step by step. Our goal is to isolate #x#. First, we should subtract #3# on both sides. That would give us

#1/2root(3)(x-7)=-1#.

Now, we divide by #1/2# on each side. This is equivalent to multiplying by #2# on both sides, which either way gives us

#root(3)(x-7)=-2#.

To get rid of the #root(3)#, we simply apply its inverse, which is cubing. So we cube both sides, and we get

#(root(3)(x-7))^3=(-2)^3=x-7=-8#.

We just add #7#, and we are left with

#x=-1#.

To confirm we are correct we should double check our work, by confirming that when #x=-1#, the earlier equation is still equal to #2#.

#1/2root(3)((-1)-7)+3=2# becomes #1/2root(3)(-8)+3=2#, or #1/2*-2+3=2#. Now, #1/2# multiplied by #-2# is #-1#, and #-1+3# is equal to #2#. Therefore, we were correct, and #x=-1#. Good job!