college algebra
posted by Anonymous on .
I need help solving this equation.
3√z+1=3
How do I do this problem? Thanks for your help.

3√z+1 = 3
3√z = 4
Now, √z is interpreted to be positive
√4 = 2, not ±2
so, there is no solution to the equation
3√z = 4
since √z is positive
However, we can go on to say that
3√z = 4
9z = 16
z = 16/9
But, this is really a spurious solution, since
3√(16/9)+1 = 3(4/3)+1 = 4+1 = 5
We cannot use 4/3 as √(16/9) unless specifically indicated.