Answer:
all B
Explanation:
when calculating:
always do the square root and power first, then parentheses have an advantage before everything else. after that you multiply/divide. only after that do you add/subtract. So, order of operations:
1. sqr roots/power (if necessary)
2. parentheses
3. multiplication/division
4. addition/subtraction
3. screenshot
if the power of a negative number is even, the number becomes positive. if the power is odd, the number remains negative. (when you multiply - by - you get +)
(-2)⁴=(-2)(-2)(-2)(-2)=(+4)(+4)=16
here, the number of minuses is even. for every minus, there's another one to multiply it by.
(-2)³=(-2)(-2)(-2)=(+4)(-2)=-8
here, there's an odd number of minuses, so if we put them in pairs, there's one left alone, which makes the number negative. (multiply - by + you get -)
What about (c²-d²)?
well, as I said c² is a positive number, because you multiply a negative by a negative. d² itself is positive, but then we add the minus in front, which makes it negative. the operation looks something like this:
((-2)²-(2)²)=
(4-(4))=
4-4
hope this helps :)