Question 64286
Solve for the variable: (square root of)(2x + 1) = -1

a) 0
b) 1
c) -1
d) -2
{{{highlight(e)}}} none of these
You can't take the square root of anything and get a negative number, so you can look at this and know that this has no solution,  however, if you didn't notice that, you would try to solve it this way.
{{{(sqrt(2x+1))^2=(-1)^2}}}
{{{2x+1=1}}}
{{{2x+1-1=1-1}}}
{{{2x=0}}}
{{{2x/2=0/2}}}
{{{x=0}}}
But when you check x=0, you will find that it's extraneous.
{{{sqrt(2(0)+1)=-1}}}
{{{sqrt(0+1)=-1}}}
{{{sqrt(1)=-1}}}
{{{1=-1}}}  Not true, so 0 is extraneous and there is no solution.
Happy Calculating!!!