The answer is A and B. I showed my work below. I hope it makes sense. Let me know if you have any questions.
Answer:
- Commutative Property of Addition.-
- 2 + 3 = 3 + 2
- Commutative Property of Multiplication.- ex. 5 × 7 = 7 × 5
- Associative Property of Addition.- ex.(2 + 3) + 6 = 2 + (3 + 6)
- Associative Property of Multiplication.- ex. (7 × 3) × 10 = 7 × (3 × 10)
- Distributive Properties of Addition Over Multiplication- ex. 2 × (2 + 8) = 2 × 2 + 2 × 8
- (2 + 8) × 10 = 2 × 10 + 8 × 10
- The reciprocal of a non zero real number a is 1/a.- ex. reciprocal of 5 is 1/5 and 5 × (1/5) = 1
Step-by-step explanation:
X = velocity of plane
y = velocity of wind
x - y = 1680/5 = 336 mph .....(1) [ plane flying against the wind]
&
x + y = 1680/4 = 420 mph....(2) [ plane flying with the wind]
Adding (1) and (2) to eliminate y gives
2x = 756
x = 378 mph is the speed of the plane with no wind.
Well if the cubic unit is one, then we can assume that the domain is -1<0