Answer
We need to prove that the triangles are not similar triangles.
Work Step by Step
In this problem, if the given proportions were true, that would mean that the triangles were similar triangles. We must prove that this is not the case. To do this, we show that one of the other proportions is not true. Thus, we find:
$$ \frac{5}{a+1} = \frac{a}{a+1} \\ 5= a$$
We check if this satisfies the given expression:
$$ \frac{a}{a+1} = \frac{a+4}{a+7} \\ \frac{5}{6}=\frac{9}{12}$$
This is not true, so we have hence proven the given proportion is not satisfied.
