Answer:
A
Step-by-step explanation:
Add 3x^2 and 5x^2 now it = 8x^2
Add -8x and -4x = -12x
look at your answer choices the only one that has 8x^2-12x is A
Answer: D. Getting at least 2 heads and Getting at least 2 tails
=========================================================
Explanation:
Choice A is not disjoint because "getting at least 1 tail" could have the sequence TTH. We see that we have two tails and exactly one head. So the events "getting exactly 1 head" and "Getting at least 1 tail" are possible to occur at the same time; therefore, they aren't disjoint events. Disjoint events are two events that cannot occur simultaneously. An example would be flipping heads and tails on the same coin at the same time.
Choice B is also not disjoint. We could have the sequence THT, which has at least one head and at least one tail. "At least" means that amount or more.
Choice C is also not disjoint. We could have the sequence HTT. This has exactly one head and at least two tails.
Choice D is the only thing left. It must be the answer. It is not possible to get 2 heads and 2 tails when Roger only flips the coin 3 times. He would need to flip the coin at least 4 times for this to happen. The portions "at least" don't even need to be considered. So this shows how choice D is disjoint.
Answer:
Step-by-step explanation:
I'm not sure if this is right
Pythagorean Theorem
a^2 +b^2 =c^2
60^2 +b^2 = 78^2
3600+b^2 = 156
-3600 -3600
b^2 =-3444
b=58.685603i
