U=-2a-3/ka, write an equation to solve for a (do not actually answer)

U=-2a-3/ka

First you need to get rid of the denominator. Do this by multiplying each side by ka.

U (ka) = - 2a - 3

Now add 2a to both sides.

Uka + 2a = - 3

You can factor this because you have a common variable.

a (Uk + 2) = - 3

Now you can divide both sides by (Uk + 2).

a = - 3 / (Uk + 2)

And that is your answer.