Consider the function f(x) = 3x2 + 7x + 2.

OK i have a problem i have to find the percentage that the price went up so i have .57 cents and then it went up to 62 cents sho

cluponka [151]

It would be ab 8.77%

3 0

3 years ago

Mr. Jackson traveled to a city 170 miles from his home to attend a meeting. Due to car trouble, his average speed returning was

Umnica [9.8K]

Answer: the average speed at which he traveled to the city is 52.9 mph

Step-by-step explanation:

Let x represent the average speed at which he traveled to the city. Due to car trouble, his average speed returning was 8mph less than his speed going. It means that the speed at which he returned is (x - 8) mph.

Time = distance/speed

Assuming the distance travelled to and from the city is the same(170 miles), then

Time spent in travelling to the city is

170/x

Time spent in travelling back from the city is

170/(x - 8)

If the total time for the round trip was 7 hours, it means that

170/x + 170/(x - 8) = 7

Multiplying both sides of the equation by x(x - 8), it becomes

170(x - 8) + 170x = 7x(x - 8)

170x - 1360 + 170x = 7x² - 56x

7x² - 56x - 170x - 170x + 1360 = 0

7x² - 396x + 1360 = 0

Applying the general formula for solving quadratic equations which is expressed as

x = [- b ± √(b² - 4ac)]/2a

From the equation given,

a = 7

b = - 396

c = 1360

Therefore,

x = [- - 396 ± √(- 396² - 4 × 7 × 1360)]/2 × 7

x = [396 ± √(156816 - 38080)]/14

x = [396 ± √118736]/14

x = (396 + 344.58)/14 or x = (396 - 344.58)/14

x = 52.9 or 3.7

Checking both values of x,

For x = 52.9

170/52.9 + 170/(52.9 - 8) = 7

= 3.2 + 3.8 = 7

Therefore, x = 52.9 mph

4 0

3 years ago

Please help with this! Will give brainliest if the answer is right!

musickatia [10]

Answer:

784

Step-by-step explanation:

caculator. of course.

4 0

3 years ago

Read 2 more answers

Which expression is NOT equivalent to 4×38? A. 4×(3×18) B.(4×3)×18 C. (4×18)×3 D. (4×3)×(4×18)

uysha [10]

Answer:

Every choice is not equivalent to 4✖️38.

Step-by-step explanation:

4✖️38=152

A. 54✖️4=216

B. 12✖️18=216

C. 72✖️3=216

D. 12✖️72=864

Every choice is not equivalent to 4✖️38.

3 0

3 years ago

.4^3Grafting, the uniting of the stem of one plant with the stem or root of another, is widely used commercially to grow the ste

11111nata11111 [884]

Answer:

0.784 = 78.4% probability that there will be at least one failed graft in the next three done

Step-by-step explanation:

To solve this question, we need to understand the binomial probability distribution and conditional probability.

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.

Conditional Probability

We use the conditional probability formula to solve this question. It is

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: No failed grafts in the first seven

Event B: At least one fail in the next three.

Intersection of events A and B:

Since the probability of a graft failling is independent of other grafts, we have that:

$P(A \cap B) = P(A)*P(B)$

So

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{P(A)*P(B)}{P(A)} = P(B)$

So we just have to find the probability of one fail in three trials.

Three trials means that $n = 3$ .

The probability is

$P(X \geq 1) = 1 - P(X = 0)$

In which

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

$P(X = 0) = C_{3,0}.(0.4)^{0}.(0.6)^{3} = 0.216$

Then

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.216 = 0.784$

0.784 = 78.4% probability that there will be at least one failed graft in the next three done

3 0

3 years ago