Question 464409
<pre>
  30dē + 34d + 8 = 0

Divide every term by 2:

  15dē + 17d + 4 = 0

Factor the left side

(5d + 4)(3d + 1) = 0

Now the principle of zero product explained:

This says (5d + 4) multiplied by (3d + 1) equals zero.

The only way that can possibly happen is for one of 
them to equal zero.

So either 5d + 4 equals zero or 3d + 1 equals 0.

So we write and solve the two equations:

5d + 4 = 0     3d + 1 = 0
    5d = -4        3d = -1
     d = {{{-4/5}}}         d = {{{-1/3}}}

There are two solutions, one for each of those two
possibilities.

Edwin</pre>