All categories

3 years ago

R^2+15r+56=0 Quadratics factoring

Mathematics

1 answer:

mylen [45]3 years ago

6 0

Step-by-step explanation:

Find the product, sum and factors which are P=56, S=15 and F=8,7 respectively.

r²+15r+56=0

replacing with the factors in the equation

=> r²+8r+7r+56=0

r(r+8)+7(r+8)=0

(r+8)(r+7)=0

=> r= –8 and –7

You might be interested in

Is 267 the largest number in the sum of 3 integers evaluated from 269?

Anni [7]

Yes. it is the largest number

4 0

3 years ago

Graph the image of this figure after a dilation with a scale factor of 2 centered at the origin.

den301095 [7]

Answer:

Here, the coordinates of the given rectangle are (1,2), (3,2), (1,-1) and (3,-1)

In the dilation by the scale factor k with centered at origin,

$(x,y)\rightarrow (kx,ky)$

Thus, If the dilation occurs by the scale factor of 2 with centered at origin,

New coordinates of the Rectangle are,

$(1,2)\rightarrow (2\times 1, 2\times 2)$

$(3,2)\rightarrow (2\times 3, 2\times 2)$

$(1,-1)\rightarrow (2\times 1, 2\times -1)$

$(3,-1)\rightarrow (2\times 3, 2\times -1)$

Thus, the coordinates of new rectangle are,

(2,4), (6,4), (2,-2) and (6,-2)

3 0

3 years ago

Read 2 more answers

It is estimated that 75% of all young adults between the ages of 18-35 do not have a landline in their homes and only use a cell

Mademuasel [1]

Answer:

a) 75

b) 4.33

c) 0.75

d) $3.2 \times 10^{-13}$ probability that no one in a simple random sample of 100 young adults owns a landline

e) $6.2 \times 10^{-61}$ probability that everyone in a simple random sample of 100 young adults owns a landline.

f) Binomial, with $n = 100, p = 0.75$

g) $4.5 \times 10^{-8}$ probability that exactly half the young adults in a simple random sample of 100 do not own a landline.

Step-by-step explanation:

For each young adult, there are only two possible outcomes. Either they do not own a landline, or they do. The probability of an young adult not having a landline is independent of any other adult, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

75% of all young adults between the ages of 18-35 do not have a landline in their homes and only use a cell phone at home.

This means that $p = 0.75$

(a) On average, how many young adults do not own a landline in a random sample of 100?

Sample of 100, so $n = 100$

$E(X) = np = 100(0.75) = 75$

(b) What is the standard deviation of probability of young adults who do not own a landline in a simple random sample of 100?

$\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{100(0.75)(0.25)} = 4.33$

(c) What is the proportion of young adults who do not own a landline?

The estimation, of 75% = 0.75.

(d) What is the probability that no one in a simple random sample of 100 young adults owns a landline?

This is P(X = 100), that is, all do not own. So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 100) = C_{100,100}.(0.75)^{100}.(0.25)^{0} = 3.2 \times 10^{-13}$

$3.2 \times 10^{-13}$ probability that no one in a simple random sample of 100 young adults owns a landline.

(e) What is the probability that everyone in a simple random sample of 100 young adults owns a landline?

This is P(X = 0), that is, all own. So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{100,0}.(0.75)^{0}.(0.25)^{100} = 6.2 \times 10^{-61}$

$6.2 \times 10^{-61}$ probability that everyone in a simple random sample of 100 young adults owns a landline.

(f) What is the distribution of the number of young adults in a sample of 100 who do not own a landline?

Binomial, with $n = 100, p = 0.75$

(g) What is the probability that exactly half the young adults in a simple random sample of 100 do not own a landline?

This is P(X = 50). So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 50) = C_{100,50}.(0.75)^{50}.(0.25)^{50} = 4.5 \times 10^{-8}$

$4.5 \times 10^{-8}$ probability that exactly half the young adults in a simple random sample of 100 do not own a landline.

8 0

2 years ago

F(x)=x^2-8x+7 in factored form

Karolina [17]

Answer:

(x-1)(x-7)

Step-by-step explanation:

To factor the equation, find two binomials which multiply to a quadratic. The quadratic's factors are found by finding two numbers that multiply to 7 and add to -8.

-1 and -7 multiply to 7 and add to -8.

(x-1)(x-7)

7 0

3 years ago

2 math questions. Please show your work if you can, I struggle with this, Thanks !!<br> 20pts

castortr0y [4]

Step-by-step explanation:

To find the solution, Tanisha can graph each side of the equation as its own function:

y₁ = log₃(5x)

y₂ = log₅(2x + 8)

The solution is where the two curves cross. From the graph, that happens at x ≈ 0.957.

desmos.com/calculator/lkukjhn3g2

5 0

3 years ago