Put parentheses around the first two terms:
Notice that occurs in two places, so let the
variable part of the middle term, in this case the whole
middle term, be equal to the letter .
That is to say we are letting
Now we square both sides:
So we substitute for in the original
equation, and for
becomes the much simpler looking equation:
Using the zero-factor property,
So now we have to substitute back.
We can tell immediately that has no
solution because square roots when written as a radical
are never negative, so that square root on the left
could not equal to -2 on the right.
So we solve
Square both sides: