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3 years ago

2 X-4y/2 if x=4 and y=-3

Mathematics

1 answer:

Dahasolnce [82]3 years ago

3 0

Step-by-step explanation:

Sub in your values

4-4(-3)/2

=4 + 12 /2

=4+ 6

=10

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What is 1.7 divided by 0.428

Mashcka [7]

3.97196261682 hope this helps!

3 0

3 years ago

Suppose that a box contains r red balls and w white balls. Suppose also that balls are drawn from the box one at a time, at rand

dybincka [34]

Answer: Part a) $P(a)=\frac{1}{\binom{r+w}{r}}$

part b) $P(b)=\frac{1}{\binom{r+w}{r}}+\frac{r}{\binom{r+w}{r}}$

Step-by-step explanation:

The probability is calculated as follows:

We have proability of any event E = $P(E)=\frac{Favourablecases}{TotalCases}$

For part a)

Probability that a red ball is drawn in first attempt = $P(E_{1})=\frac{r}{r+w}$

Probability that a red ball is drawn in second attempt= $P(E_{2})=\frac{r-1}{r+w-1}$

Probability that a red ball is drawn in third attempt = $P(E_{3})=\frac{r-2}{r+w-1}$

Generalising this result

Probability that a red ball is drawn in [tex}i^{th}[/tex] attempt = $P(E_{i})=\frac{r-i}{r+w-i}$

Thus the probability that events $E_{1},E_{2}....E_{i}$ occur in succession is

$P(E)=P(E_{1})\times P(E_{2})\times P(E_{3})\times ...$

Thus $P(E)$ = $\frac{r}{r+w}\times \frac{r-1}{r+w-1}\times \frac{r-2}{r+w-2}\times ...\times \frac{1}{w}\\\\P(E)=\frac{r!}{(r+w)!}\times (w-1)!$

Thus our probability becomes

$P(E)=\frac{1}{\binom{r+w}{r}}$

Part b)

The event " r red balls are drawn before 2 whites are drawn" can happen in 2 ways

1) 'r' red balls are drawn before 2 white balls are drawn with probability same as calculated for part a.

2) exactly 1 white ball is drawn in between 'r' draws then a red ball again at $(r+1)^{th}$ draw

We have to calculate probability of part 2 as we have already calculated probability of part 1.

For part 2 we have to figure out how many ways are there to draw a white ball among (r) red balls which is obtained by permutations of 1 white ball among (r) red balls which equals $\binom{r}{r-1}$

Thus the probability becomes $P(E_i)=\frac{\binom{r}{r-1}}{\binom{r+w}{r}}=\frac{r}{\binom{r+w}{r}}$

Thus required probability of case b becomes $P(E)+ P(E_{i})$

= $P(b)=\frac{1}{\binom{r+w}{r}}+\frac{r}{\binom{r+w}{r}}\\\\$

7 0

4 years ago

What is the area of a sector with a central angle of 3pi/5 radians and a diameter of 21.2cm

Elenna [48]

Answer: 105.84 cm^2

To find the answer, first you have to start by finding the percent of the circle in the sector. Convert the radians given to 108 degrees. 108 out of 360 is 30%.

Now, find the area of the circle. It's pi x r^2, so the area is 352.810.

Multiply this by 30% to find our area of 105.84 cm^2

8 0

3 years ago

I NEED THIS ANSWER QUICK (5 1/6 - x) ∙ 2.7 - 5 3/4 = -1.25 what is x

fgiga [73]

Answer:

x = 3 1/2

Step-by-step explanation:

You could simplify the given equation first, then solve the resulting 2-step linear equation. It might work better to undo the operations done to the variable.

<h3>Solution</h3>

(5 1/6 -x)(2.7) -5 3/4 = -1 1/4 . . . . . given

(5 1/6) -x)(2.7) = 4 1/2 . . . . . . . add 5 3/4 to both sides

(5 1/6 -x) = 4.5/2.7 = 5/3 . . . divide by 2.7

31/6 -10/6 = x . . . . . . . . . . add x-5/3, use common denominators

21/6 = x = 7/2

x = 3 1/2

6 0

2 years ago

What is the least common denominator of these fractions: 1/8, 1/5 and 1/10?

Alex

You must find the least common multiple of 8, 5, and 10. In this case the least common denominator is 40. 8•5= 40, 5•8= 40, and 10•4= 40. Answer: 40.

3 0

4 years ago