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3 years ago

60% of the students in class are girls. If there are 15 girls, how many students are in class?

1 answer:

4 0

25

If 15 is 60% of a number, it is 3/5 of the whole. Since 5 goes into 25 5 times, and 5 goes into 15 3 times, 15 is the 3/5 of 25.

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Factor f(x) = 15x^3 - 15x^2 - 90x completely and determine the exact value(s) of the zero(s) and enter them as a comma separated

Illusion [34]

Answer:

$x=-2,0,3$

Step-by-step explanation:

We have been given a function $f(x)=15x^3-15x^2-90x$ . We are asked to find the zeros of our given function.

To find the zeros of our given function, we will equate our given function by 0 as shown below:

$15x^3-15x^2-90x=0$

Now, we will factor our equation. We can see that all terms of our equation a common factor that is $15x$ .

Upon factoring out $15x$ , we will get:

$15x(x^2-x-6)=0$

Now, we will split the middle term of our equation into parts, whose sum is $-1$ and whose product is $-6$ . We know such two numbers are $-3\text{ and }2$ .

$15x(x^2-3x+2x-6)=0$

$15x((x^2-3x)+(2x-6))=0$

$15x(x(x-3)+2(x-3))=0$

$15x(x-3)(x+2)=0$

Now, we will use zero product property to find the zeros of our given function.

$15x=0\text{ (or) }(x-3)=0\text{ (or) }(x+2)=0$

$15x=0\text{ (or) }x-3=0\text{ (or) }x+2=0$

$\frac{15x}{15}=\frac{0}{15}\text{ (or) }x-3=0\text{ (or) }x+2=0$

$x=0\text{ (or) }x=3\text{ (or) }x=-2$

Therefore, the zeros of our given function are $x=-2,0,3$ .

7 0

4 years ago

Fun question: how can you make 11 out of 4 sevens?

Vladimir [108]

Answer: (7+1/7) *(7+7)

Step-by-step explanation:

7 0

3 years ago

What is the area of the trapezoid??

lawyer [7]

Area of trapezoid formula:
A = 1/2(b1 + b2) h
A = 1/2(2.4 + 9)(8.2)
A = 1/2(11.4)(8.2)
A = 46.74 ml^2

3 0

4 years ago

34. Find each of the following probabilities when n indepen- dent Bernoulli trials are carried out with probability of success p

mr Goodwill [35]

Answer:

A.) (1 - p)^n

B.) 1 - (1 - p)^n

C.) (1 - p)^n + np*(1-p)^(n-1)

D.) 1 - (1 - p)^n - np*(1-p)^(n-1)

Step-by-step explanation:

General form of a binomial probability :

P(x = x) = nCx * p^x * q^(n-x)

q = 1 - p ; n = number of trials ; x = number of successes ; p = probability of success

A.) probability of no successes ;

P(x = 0) = nC0 * p^0 * (1 - p)^(n-0)

P(x = 0) = 1 * 1 * (1 - p)^n

P(x = 0) = (1 - p)^n

Probability of atleast one success = 1 - P(no success)

P(x ≥ 1) = 1 - P(x = 0)

P(x = 0) = (1 - p)^n

P(x ≥ 1) = 1 - P(x = 0) = 1 - (1 - p)^n

Probability of at most one success

P(x ≤ 1) = p(x = 0) + p(x = 1)

P(x = 0) = (1 - p)^n

P(x = 1) = nC1 * p^1 * (1 - p)^(n-1)

P(x = 1) = n * p * (1 - p)^(n-1) = np*(1-p)^(n-1)

P(x ≤ 1) = (1 - p)^n + np*(1-p)^(n-1)

Probability of atleast two successes:

(1 - probability of at most 2 successes)

P(x ≥ 2) = 1 - P(x ≤ 1)

P(x ≥ 2) = 1 - (p(x = 0) + p(x = 1))

P(x ≥ 2) = 1 - p(x = 0) - p(x = 1))

P(x ≥ 2) = 1 - (1 - p)^n - np*(1-p)^(n-1)

6 0

3 years ago

If m = 3 and n = 2, then m 2 - n 2 is equal to _____. 2 5 1 13

bekas [8.4K]

Answer:

6-4=2

Step-by-step explanation:

3x2=6 2x2=4

8 0

3 years ago

Read 2 more answers