Δabc will undergo two transformations to give δa′b′c′. which pair of transformations will give a different image of δabc if the order of the transformations is reversed?

The correct answer to this question would be:

“A rotation 90° counterclockwise about the origin followed by a reflection across the y-axis”

The best way to do this is to visualize or draw any triangle ABC then go through the transformations to see the result.    In general, reflections and translations in reversed order should give us the same image. However the answer to this question will give us a different image.