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3 years ago

What is (4x+3)(x-7)=90

2 answers:

8 0

$(4x+3)(x-7)=90\\
Distribute\\
4x^{2}-28x+3x-21=90\\
4x^{2}-25x-21=90\\
4x^{2}-25x-101=0\\
\\
101\ is\ a\ prime\ number,\ so\ use\ the\ quadratic\ equation.\\
x= \frac{-b+-\sqrt{b^{2}-4ac}}{2a} \\
 \frac{-(-25)+-\sqrt{(-25)^{2}-4*4*(-101)}}{2*4} \\
 \frac{25+-\sqrt{625+1616}}{8} \\
x= \frac{25+-\sqrt{2241}}{8} \\
So\ x= \frac{25+\sqrt{2241}}{8}\ and x= \frac{25-\sqrt{2241}}{8} \\
These\ come\ out\ to\ be\ x=9.0424... \ and\ x=-2.7924...$

Ivan3 years ago

6 0

It would be 16 i say

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A rectangular exercise mat has a perimeter of 36 feet . The length mat is twice the width. Write and solve an equation to determ

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ANSWER

72 square feet

EXPLANATION

The perimeter of a rectangle is given by:

P= 2l+2w

It was given that, the perimeter of the rectangular mat, is 36 feet.

36= 2l+2w

Divide through by 2.

$18 = l + w...(1)$

It was given also that, the length of the mat is twice its width.

This implies that,

$l = 2w ...(2)$

Put equation (2) into equation (1) to get,

$18 = 2w + w$

$18 = 3w$

$w = 6 \: ft$

This means that the length is 12 ft.

The area of the rectangular mat is

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3 years ago

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Liono4ka [1.6K]

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3 years ago

Read 2 more answers

The mean number of daily surgeries at a local hospital is 6.2. Assume that surgeries are random, independent events. (a) The cou

Scilla [17]

Answer:

a) correct option is

Poisson distribution is 6.2 and standard deviation is 2.49

b) probability for only 2 or less than 2 surgeries in a given day is 0.0536

Step-by-step explanation:

Given data:

mean number is given as 6.2

correct option is

Poisson distribution is 6.2 and standard deviation is 2.49

we know that variance is given as $\sigma^2 = mean = 6.2$

hence, standard deviation is given as $\sqrt{6.2} = 2.48998$

thus standard deviation is 2.49

correct option is

Poisson distribution is 6.2 and standard deviation is 2.49

b) probability for only 2 or less than 2 surgeries in a given day is

$P(X \leq 2) = P(X =0) + P(X =1) + P(X =2)$

$= \frac{e^{-6.2} 6.2^0}{0!} +\frac{e^{-6.2} 6.2^1}{1!} +\frac{e^{-6.2} 6.2^2}{2!}$

= 0.002029 + 0.012582+ 0.039006

= 0.053617

= 0.0536

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2 years ago

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Step-by-step explanation:

(A) ∠3 and ∠6 forms the interior angles on the same side of the transversal. Thus, this option is incorrect.

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2 years ago

Explain why if a runner completes a 6.2â-mi race in 32 âmin, then he must have been running at exactly 11 âmi/hr at least twice

MA_775_DIABLO [31]

Answer:

Accelerating to top speed, deaccelerating to finish line.

Step-by-step explanation:

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This means that, in order to run the full 6.2 miles, the runner needs to reach a speed over 11 mph. Assume he starts from rest, while accelerating the runner reaches, and the surpasses, the 11 mph mark. Since his speed at the finish line is zero, the runner has to deaccelerate from his current running speed (which should be higher than 11 mph), passing through 11 mph and reaching zero at the finish line.

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3 years ago