Hello

This is my first time using WA and also it was a looong time since I took an Algebra class, and now I am taking Calculus. While I understand the terms and procedures, I get lost in the algebra parts.

Consider this part of an exercise and see the multiplication in the numerator:

As you can see, the product from the multiplication on the fraction numerator according to my professor, is (x^2 + x) - x^2 but when I try to multiply that numerator in WA, the result is x = 0. Is this because WA is just giving me the value of x? Here is my input on WA:

Solve (sqrt(x^2+x) - x) (sqrt(x^2+x) + x)

So what can I do to obtain same results as we do in class?

Please... thank you!!