Part a
For horizontal 8*50% = 4 and for vertical 12*75%= 9.
So these values are less than the originals so the new frame is a reduction.
Part b
For horizontal 8*125% = 8*1.25 = 10 and for vertical 12*140% = 12*1.4 =16.8
So these values are greater than the originals sothe new frame is a enlargement.