SOMEBODY HELP ME PLEASE

""What is wrong with the solution:

x(x+3)=9
x=9 or x+3=9
x=6

So, the roots are 6 & 9""

i dont understand 

Question

SOMEBODY HELP ME PLEASE

""What is wrong with the solution:

x(x+3)=9
x=9 or x+3=9
           x=6

So, the roots are 6 & 9""

i dont understand 

anonymous · Answer

Suppose $x=9$ is a solution. Does the equation still hold?
$$9(9+3)=9~~?$$

anonymous · Answer

The answer is no. You can only apply the step you used if the equation were equal to 0.

What you should have done:
$$x(x+3)-9=0\
x^2+3x-9=0$$
Then find the roots by factoring or applying the quadratic formula.

acxbox22 · Answer

using the zero product rule the function has to be equal to zero in order to solve
for example
x(x+3)=0
x=0 and x=-3
x(x+3)=9<----not equal to zero

anonymous · Answer

Thank you to yall!!!!