This is solved by breaking the equasion down.
2 { 5 [12 + 5 (500 - 100) + 399 ]}
2 { 5 [12 + 5 (400) + 399]}
2 { 5 [12 + 2000 + 399]}
2 { 5 [2411]}
2 {12055}
24110
Is this the answer you were looking for?
Answer:
68
Step-by-step explanation:
First you multiply 8 and 4 to get 32 and that shows you how many campers have agreed to help. Next you have to subtract 32 from 100 to know how many more people you need.
If you estimated 3.7 to 4 and 5.1 to 5 the answer would be 20. You would have 20 and now you can think is 20 a reasonable answer for 3.7x5.1. The answer for 3.7x5.1=18.87, so the answer is yes.
Hope that helped:)