When it says "What if the carrots were 0.50 less a pound," it wants you to subtract .50 from 15.30, which gives you 14.80.
Now that we've found this, we need to multiply the new cost by 8.5 pounds:
14.80 * 8.5 = 125.8
Therefore, Victoria would have paid $125.80 if the carrots were 50 cents less a pound.
Hope this helps! :)