Wo hai you wen ti...

[BlasianAsian]

How the heck do you do these? O.O

Simplify:

[unparseable or potentially dangerous latex formula]

Answer: [unparseable or potentially dangerous latex formula]

Abby rides a ski lift up a hill at the rate of 4 mph and skis back down the hill at the rate of 48 mph. If she completes the trip in 18 minutes, approximately how many miles is it from the bottom to the top of the hill?

If [unparseable or potentially dangerous latex formula], then b equals...

Answer: -1

In the expansion of [unparseable or potentially dangerous latex formula], the coefficient of the [unparseable or potentially dangerous latex formula] is...

Answer: 56

What is the unit vector in the same direction as <-24,7>?

Answer: [unparseable or potentially dangerous latex formula]

If Shauna flips a coin 4 times, what is the probability that she will get two consecutive heads on any of the four flips?

Answer: 3/16

Tara makes a jar of lemonade that is 15% sugar by combining 4 ounces of a solution of lemonade that is 20% sugar with 3 ounces of a solution of lemonade with an unknown amount of sugar. To the nearest tenth, what is the percentage of sugar in the 3 ounce solution?

Answer: 8.3

Which of the following sets is closed under multiplication and addition?

A) {2,4,6,...} B) {1,-1} C) {1/0} D) {...,-3, -2, -1} E) none of the above

Answer: A

It took William 200 sec to row 400 yards. The return trip took 50 sec. What was William's speed?

Answer: 5 yards/sec

At 2:16 PM, the hour and the minute hands of a clock form an acute angle of _____ radians.

Answer: [unparseable or potentially dangerous latex formula]

How many ways can you pick 5 distince numbers from the integers 1 to 5 inclusive?

Answer: 3003

The universal set [unparseable or potentially dangerous latex formula] Subset [unparseable or potentially dangerous latex formula] and [unparseable or potentially dangerous latex formula]. How many elements are in the complement of [unparseable or potentially dangerous latex formula].

Answer: 3

Oh god, meet's tommorrow. Hopefully, everything won't crash and burn. Thanks again for the help! I know it's a lot.

[nsguy1350]

[unparseable or potentially dangerous latex formula].

I'm not sure how to do this one.

Ouch, I must be off today, can't do this one either.

This can be simplified to [unparseable or potentially dangerous latex formula], and the coefficient of the fourth term, the one with x^5, should be [unparseable or potentially dangerous latex formula].

I don't even know what that question even says! The answer is very confusing.

I had a strategy, but the answer make no sense. If you can flip a coin twice and have a 25% chance of getting two heads consecutively, how do you get two extra tries and have less chance?

You know the final solution is 7 ounces. If it's 15% sugar, then you know that 1.05 ounces is sugar. If the 3 ounce solution has 20% sugar, then there is already .8 ounces of sugar in the new solution. This leaves .25 ounces for the 3 ounce solution. .25/3 = .08333... ~ 8.3%.

A is correct, because whenever you multiply or add two elements of A, you get another element of A. B is wrong because adding 1 and -1 is 0, which is not a member of that set. Same with C and D. Is C a typo? Should it just be (0,1) instead? If C is not closed, apparently, you can determine set closure through repeated elements.

Let d be the distance, v be William's speed, c be the speed of the water, and t be the time taken to travel. Since [unparseable or potentially dangerous latex formula], by regular physics, we can substitute the constant distance, and plug in the appropriate values of time and speed. We get that [unparseable or potentially dangerous latex formula], and [unparseable or potentially dangerous latex formula]. Then, you just solve for c and v, with two equations in a system of equations.

In degrees, the angle formed by a clock is [unparseable or potentially dangerous latex formula]. Plug in your minutes and hours, then convert to degrees, and you're good.

3003? I'm lost. I was thinking maybe the balls-and-pins formula, to get 9C5, but apparently not.

[unparseable or potentially dangerous latex formula]. The complement is the set that contains all elements not in this set that are in the universal set, so the missing element is [unparseable or potentially dangerous latex formula]. This means 1 element.

Hopefully, I did the problems that I could do correctly. I need some work in Math as well!

[graduatingsoon]

o hi! I see you have some solved, so I'll just do the rest:

cos2x+1 / sin2x
(cos^2 x) * 2/sin2x
(cos^2 x) * 2 / 2sinxcosx
cos^2 x / sinx cosx
cosx/sinx
cot x
hope that was clear. next...

edit: Abby rides a ski lift up a hill at the rate of 4 mph and skis back down the hill at the rate of 48 mph. If she completes the trip in 18 minutes, approximately how many miles is it from the bottom to the top of the hill?
4mph=1/15 mpm
48mph=4/5 mpm
1/15(t)=4/5 (18-t)
t=16.615
1/15(16.91)=1.108 mi
check & it works! :D (I think)
next problem coming up...

edit: If sqrt(3-2sqrt(2))=sqrt(a)+b, then b equals...
I'll come back to this one lol
so here we go:
sqrt(3-sqrt(8))=sqrt(a)+b
3-sqrt(8)=a+2bsqrt(a)+b^2
3=a+b^2 so a=3-b^2
-sqrt(8)=2bsqrt(a)
-sqrt(8)=2bsqrt(3-b^2)
and we see that b=-1 with some simple algebra. cool problem!

edit:What is the unit vector in the same direction as <-24,7>?
basically it's asking what is the vector *of length 1* in the same direction?
your answer is correct, but it simplifies to <-24/25,7/25> :)
next problem coming...

edit:If Shauna flips a coin 4 times, what is the probability that she will get two consecutive heads on any of the four flips?
1/4 HH+
1/8 THH+
1/16 TTHH+
1/16 HTHH=
1/2 I believe. 3/16 seems to be wrong :S
...

edit:Which of the following sets is closed under multiplication and addition?
A) {2,4,6,...} B) {1,-1} C) {1/0} D) {...,-3, -2, -1} E) none of the above
well let's take a look:
A) all positive multiples of 2. adding two pos mults of 2 gives a sum that is a mult of 2. multiplying two pos mults of 2 gives a mult of 2 as a product. so A works :)
B) 1+ -1 =0 so it doesn't work because 0 is not in the set
C) 1/0 what? can't divide by 0 lol
D) (-2)(-1) =2 and 2 is not in the set
E) not none of the above because A worked
so answer is A
more...

How many ways can you pick 5 distince numbers from the integers 1 to 5 inclusive?
lolwat?? it probably says distinct but even then idk what it's asking...

The universal set U = {M,I,C,H,I,O,K,A,K,U}. Subset H = {H,I,A,K,U} and C = {C,O,A,C,H}. How many elements are in the complement of H U C?.
(H U C) is {H,I,A,K,U,C,O,H}
complement means what you need to add to (H U C) to get to the universal set, U
so we look and see that we need M, I, K because in the first set there are 2 Ks and 2 Is
so the answer is 3. although nsguy1350 might be right (and I wrong). idk :/

anyway.. fun practice. tell me if I got any wrong :o