Find all roots.

(x+4)(x-2) = 0

then

x(x+2)(x+5) = 0

how do you do this?

You are already in the last step. Using the Zero Property of Multiplication, we can determine that finding a value of x that makes one expression equal zero will make the whole equation equal zero. 

If you set x = -4 in the first equation, then 0 * -6 = 0. The equation is solved. 
So, for the first equation, x = 2 and x = -4. 

For the second equation, x = 0, x = -2, and x = -5. 

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