Hello, I hope this is in the correct forum. If not, please direct me to the correct place. It's been 20 years since I've had to do any serious math, and I'm quite rusty.

In the equation D/E=(A/B)/(G/H) how do I solve for D when I don't know E, but I know the result of D/E? How would I solve for E when I don't know D, but I know the result of D/E?

Thank you.