Solve for a

U+ka=ba

The ans is a = U / (b - k)

Step-by-step explanation:

If U + ka = ba, then we can also say ba = U + ka. We can now collect like terms

ba - ka = U

since a is common term to both ba and ka, we can have

a (b - k) = U

If we divide both sides by (b - k), we can now have

a = U / (b - k)