8x-6y=-96 add to this -4 times the second equation...
-8x-12y=-48
___________
-18y=-144
y=8, this makes 8x-6y=-96 become:
8x-48=-96
8x=-48
x=-6
so the solution to the system of equations is the point:
(-6,8)
Answer:
is therr more to that question
Step-by-step explanation:
<span>The answer would be 20.
The question is asking you to find the value of the expression for when c = 100, so we have to put 100 where c is in the equation. Given that fact, we start with c/5, then put the 100 in for c.
c/5 = ??
100/5 = 20. </span>
There are 10 chips altogether. 4 of them are white.
4/10 is the chance of lifting out a white chip
There are 3 of them left and 9 chips altogehter.
4/10 * 3/9
12/90
4/30
2/15
Comment
(my edit) it is not that 2/15 is wrong (although it is not entirely right).
1/3 is the correct answer if you assume that what happened during the first draw has nothing to do with what will happen on the second. It is like saying if you throw 11 heads in a row with a fair coin, what are the chances of throwing a heads on the 12th throw? The answer is 1/2. That is the same kind of question you have asked.
The two of us who have responded have really responded to what are the chances of drawing 2 white chips. The question really does not restrict us in a way that prevents us from saying that. I'll stick with
B <<<< answer
but I think it would be nice if the writer of the question made it clear that 1/3 should be the proper answer. I am glad you came back and posted the right answer. It makes me think.
The semi right answer is B <<<<----
If my reasoning bothers anybody, I'll reedit again. I'm only leaving it because sometimes a mistake is more instructive than a given answer.
Let X be the national sat score. X follows normal distribution with mean μ =1028, standard deviation σ = 92
The 90th percentile score is nothing but the x value for which area below x is 90%.
To find 90th percentile we will find find z score such that probability below z is 0.9
P(Z <z) = 0.9
Using excel function to find z score corresponding to probability 0.9 is
z = NORM.S.INV(0.9) = 1.28
z =1.28
Now convert z score into x value using the formula
x = z *σ + μ
x = 1.28 * 92 + 1028
x = 1145.76
The 90th percentile score value is 1145.76
The probability that randomly selected score exceeds 1200 is
P(X > 1200)
Z score corresponding to x=1200 is
z = 
z = 
z = 1.8695 ~ 1.87
P(Z > 1.87 ) = 1 - P(Z < 1.87)
Using z-score table to find probability z < 1.87
P(Z < 1.87) = 0.9693
P(Z > 1.87) = 1 - 0.9693
P(Z > 1.87) = 0.0307
The probability that a randomly selected score exceeds 1200 is 0.0307
