Im not really sure if im right but i think the answer is 140-
Explanation:
I added 30+10 which equalled 40 and then i noticed the circle which would equal 360 and subtracted it from the 40 however that got me more then i needed since it wasnt one of the choices. Then i thought hmm maybe its a supplementary angle which usually equals 180 so i subtracted it from 40 which got me 140! Like i said i dont know if im right or not :(
Answer:
right square pyramid A≈742.98
Step-by-step explanation:
Height ; 40
base area ; 70
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)
I hope this helps you
6r-7r=13-7
-r=6
r= -6