Although Gabe knows the answer to the algebra problem, he cannot seem to work out the steps and reach his desired goal. So, Gabe tries working backward from the answer to the starting point. This strategy describes a
a. syllogism.
b. heuristic.
c. prototype.
d. dimension of the semantic differential.

a. syllogism.

Explanation:

Syllogism is defined as the logical application of reasoning by someone inorder to arrive at a particular conclusion. This conclusion could only be reached from the analysis of the two or more premise statement found in it and could be applied in the forward other or reverse other.

An example, If a statment says

"All birds lay eggs."

Swan is a bird.

Applying syllogism, it could be logically concluded that since Swan is a bird, it would also falls in the categories of those that lays eggs hence "Swan laying eggs"being the conclusion.