x(x+1)=0

x = 0, -1

There are 2 answers. Once when x is equal to 0. The other when x+1=0

she says x^2 + x = x^3

this is wrong, you can clearly see this by putting x equal to 3

3^2 + 3 is equal to 12

but x^3 when x is 3 is not 12 it is 3^3 = 27

the equation x^2 + x can not be simplified any further than this

if you want to know when x^2 + x is equal to zero then the first person was right when he says that this happens when x is equal to 0 or when x is equal to -1

Try taking out the common variables.

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x^2 + x =

x*x + x =

x(x+1)

thats for sure !!!

x^2 + x^2 = X^4

because x has simply an exponent one !!!