use the zero product property to solve the equation

The Zero Product Property states that any real number multiplied by 0, will equal zero.

When given an equation like a*b=0, either a=0, b=0, or both, in order to result in zero.

To solve your equation, you must set both factors equal to zero:

d+3/4=0 and d+5/8=0

Now you can subtract both sides of each equation to find d.