Question

Solve: 5x2 + 25x = 0.

Answer 1

So we frist need to simpleflie
5x2 + 25x = 0
witch is 
25x + 5x2 = 0

5x(5 + x) = 0

so we dont need the factor 5x

so that means the frist x=0

and the secon one 
5 + x = 0

but we still add -5 to both sides 

so it would end up like this 

x = 0 + -5 

with then you redude that it is 

x=-5

so it x=0, -5

Answer 2

     5x² + 25x = 0
5x(x) + 5x(5) = 0
      5x(x + 5) = 0
            5          5
        x(x + 5) = 0
x = 0    or    x + 5 = 0
                       - 5  - 5
                         x = -5