Hello :)
The first one would be a rotation because it was easily rotated upward , it looks like it was rotated maybe 90°, The second one would be translation because it is simply moved upward and moved slightly to the right without be resized, rotated, or anything. The third one would definitely be a reflection because it appears to be flipped across the x axis. The fourth one i'm not really sure but i'm going to guess it is a rotation because it is turned in a different direction from the original figure.
You should get it now from my previous answer.
But to apply it.
9 - 8b + 6b
9 + (-8b + 6b) <- Collect like bases (b)
9 + (-2b)
9 - 2b
Therefore it simplified is 9 - 2b
8. Dilation of 0.5 hope this helps :)