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2 years ago

Complete the steps in solving the quadratic function 7x – 9 = 7x2 – 49x by completing the square

Mathematics

1 answer:

siniylev [52]2 years ago

4 0

Answer:

x={-sqrt(103/7)+4, sqrt(103/7) +4}

Step-by-step explanation:

Subtract 7x from both sides: 7x^2-56x=-9

Divide both sides by 7: x^2-8x=-9/7

Solve for a (2ax=-8x): -4

Plug a back in: -9/7+(-4)^2=103/7

Complete the square: (x-4)^2=103/7

Therefore, x={-sqrt(103/7)+4, sqrt(103/7) +4}

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Simplify the radical expression

denis-greek [22]

Answer:

Step-by-step explanation:

$\sqrt{36 {x}^{2} } = \sqrt{36} \times \sqrt{ {x}^{2} }$

Square of 36 is 6. Square of x^2is x.

$6x$

3 0

2 years ago

Karen wants to advertise how many chocolate chips are in each Big Chip cookie at her bakery. She randomly selects a sample of 60

Umnica [9.8K]

Sample mean : \overline{x}=10.6x=10.6

Standard deviation : s=1.7s=1.7

Significance level : \alpha:1-0.95=0.05α:1−0.95=0.05

Critical value : z_{\alpha/2}=1.96

Hence the 95% confidence interval for the number of chocolate chips per cookie for big chip cookies= (10.1989,\ 11.0011)(10.1989, 11.0011)

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2 years ago

Show that one zero of 8x230x27 is the square of the other.

murzikaleks [220]

Answer:

8x2-30x+27 has one root (9/4) the square of the other (3/2)

Step-by-step explanation:

8x2+30x+27 = (2*x+3)*(4*x+9) => solution = {-3/2, -4/9}

One is not the square of the other because squares are positive.

8x2-30x+27 = (2*x-3)*(4*x-9) =>

solution = {3/2, 4/9} since (4/9 = (3/2)^2, therefore the preceding question is correct.

7 0

3 years ago

Which statement is true?

gayaneshka [121]

Answer:

Option: C is the correct answer.

C. Buying a needle and buying thread are dependent events.

Step-by-step explanation:

let A denotes the events of buying a thread.

and B denote the event of buying a needle.

Then A∩B denote the event of buying a needle and a thread.

Also let P denote the probability of an event.

i.e. we are given:

P(A)=0.15

Also P(B|A)=0.25

As we know that:

$P(B|A)=\dfrac{P(A\bigcap B)}{P(A)}\\\\i.e.\\\\0.25=\dfrac{P(A\bigcap B)}{0.15}\\\\i.e.\\\\P(A\bigcap B)=0.0375$

As we know that when two events A and B are independent then,

P(A∩B)=∅

otherwise they are dependent events.

Hence, option: C is the correct answer.

6 0

2 years ago

Read 2 more answers

In which quadrants of the coordinate plane is the shaded region of the system located? y ≥ x y ≤ x + 4

Ksivusya [100]

I drew these, as I just did these in math not too long ago. When I shaded it, it was in all four quadrants.

6 0

3 years ago

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