15. 
Step 1: Distribute the subtraction sign to all the numbers in the second set of parentheses...


Step 2: Combine like terms (
's go with
's)




Step 3: Combine like terms (
's go with
's)




Step 4: Combine like terms (normal numbers go with normal numbers)

1 + 2
3

You were correct!
16. 
I don't really know how to explain this one but I got: (7m-6n)(7m-6n)
Answer:
55/100
Step-by-step explanation:
Multiply 20 by 5 to get 100 so you multiply 11 by 5 to get 55
Since 7 yd is 21 ft you will have to
add 15 ft to 21 ft (36 ft)
and then divide by two
your answer is 18 ft
153.86 is the answer :) you’re welcome.