B-y is the another factor
For the first part you need to find 85% of 16,000. its 13,600. you get this by multiplying .85 by 16,000.
for part two, i don't know how to show the work, but 816 is 96% of 850.
sorry about that, but i hope it helps
5x=39 x stands for the age of bob so 39/5 =7.8 which is rounded up to 8 and if you multiply 8 by 5 you get 40 but if you multiply 7.8 by 5 you get 39 so his age would be 7.8 years old.
31cm is the side of the new square and this the largest area shape in square