If x(x+4)(2x-15)(x-1)(x+2) = 0, then what is the product of maximum and minimum value of x?

I could find it by multiplying all and finding the root but i there a easy way to find the roots or multiply between brackets ..or by seeing this equation can i deduce that 0 is min value so product will be zero ..my main question is how to find the max and min of a given equation