Final answer:
The solution involves algebraic manipulation to isolate and solve for 'a' in the given equation A = atb. The question appears to be part of a larger set of physics problems, which includes quadratic equations and kinematics.
Step-by-step explanation:
The solution to the question appears to have been split into parts, but there are some inconsistencies in the presentation of the question which may lead to confusion. However, based on one interpretable segment, solving for 'a' in the expression A = atb likely involves separating 'a' on one side of the equation. This step may involve dividing both sides by 'tb' to isolate 'a', resulting in a = A/(tb).
For the other mathematical expressions provided, it seems like the solutions are for different types of physics problems, including quadratic equations and kinematics. However, without the full context or clarity in the notation, it's challenging to provide a concrete step-by-step explanation for each part.
Overall, to solve for a when given an equation of this kind, you will typically need to rearrange the equation algebraically to isolate 'a' on one side of the equation, and then compute the value using the known variables.