To solve this equation, we can start by expanding the left side:

$x+3$$x+1$$x+5$$x+7$ + 16 = 0

Expanding the left side:

$x^2+4x+3$$x^2+12x+35$ + 16 = 0

Now, multiply the two quadratic expressions:

x^4 + 16x^3 + 71x^2 + 140x + 105 + 16 = 0

Combine like terms:

x^4 + 16x^3 + 71x^2 + 140x + 121 = 0

Now the equation is in the form of a quartic equation which can be difficult to solve. One way to solve it is by factoring or using numerical methods.