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3 years ago

11

Sean missed 8 questions when he took his quiz for the first time. when he took it the second time he only missed 3 questions. By

what percent did the number of questions he missed decrease?

1 answer:

Ivanshal [37]3 years ago

8 0

Answer:

37.5

Step-by-step explanation:

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Jorge finish 1/4 of a level of his computer game in 1/3 of the air at this rate how many hours will it take to complete one leve

aliya0001 [1]

To solve this, we'd need an answer with a whole level, which means we'll multiply everything by 4. This would mean that 1/3 is also multiplied by 4, making 4/3. Which means a whole level is made in 4/3 hours or 1 1/3 hours.

5 0

3 years ago

at a school number of boys:number of girls = 9:7 . There are 116 more boys than girls. Work out the total number at the school

Westkost [7]

612 Boys and 476 Girls

8 0

3 years ago

A ramp 18 ft long rises to a platform. The bottom of the platform is 13 ft from the foot of the ramp. Find x, the angle of eleva

Varvara68 [4.7K]

Answer:

The answer to your question is: Ф = 43.95°

Step-by-step explanation:

Data

length = 18 ft

distance bottom to is 13 ft

x = angle = ?

Formula

cos Ф = opposite side / hypotenuse

Process

cos Ф = 13 ft / 18 ft substitution

cos Ф = 0.72 simplify

Ф = cos⁻¹ (0.72)

Ф = 43.95° result

8 0

3 years ago

The following integral requires a preliminary step such as long division or a change of variables before using the method of par

shtirl [24]

Division yields

$\dfrac{x^4+7}{x^3+2x} = x-\dfrac{2x^2-7}{x^3+2x}$

Now for partial fractions: you're looking for constants <em>a</em>, <em>b</em>, and <em>c</em> such that

$\dfrac{2x^2-7}{x(x^2+2)} = \dfrac ax + \dfrac{bx+c}{x^2+2}$

$\implies 2x^2 - 7 = a(x^2+2) + (bx+c)x = (a+b)x^2+cx + 2a$

which gives <em>a</em> + <em>b</em> = 2, <em>c</em> = 0, and 2<em>a</em> = -7, so that <em>a</em> = -7/2 and <em>b</em> = 11/2. Then

$\dfrac{2x^2-7}{x(x^2+2)} = -\dfrac7{2x} + \dfrac{11x}{2(x^2+2)}$

Now, in the integral we get

$\displaystyle\int\frac{x^4+7}{x^3+2x}\,\mathrm dx = \int\left(x+\frac7{2x} - \frac{11x}{2(x^2+2)}\right)\,\mathrm dx$

The first two terms are trivial to integrate. For the third, substitute <em>y</em> = <em>x</em> ² + 2 and d<em>y</em> = 2<em>x</em> d<em>x</em> to get

$\displaystyle \int x\,\mathrm dx + \frac72\int\frac{\mathrm dx}x - \frac{11}4 \int\frac{\mathrm dy}y \\\\ =\displaystyle \frac{x^2}2+\frac72\ln|x|-\frac{11}4\ln|y| + C \\\\ =\displaystyle \boxed{\frac{x^2}2 + \frac72\ln|x| - \frac{11}4 \ln(x^2+2) + C}$

7 0

2 years ago

In 2007, the population of Ecuador was estimated at

swat32

Answer:

In 2012 , the population will be 15 million

Step-by-step explanation:

We start by setting up an exponential equation that defines the increase

P(t) = I(1 + r)^t

P(t) represents the present population = 15 million

I is the population in 2007 which is 13.8 million

r is 1.6% = 0.016

t is what we want to calculate

15 million = 13.8 million (1 + 0.016)^t

15/13.8 = (1.016)^t

1.09 = (1.016)^t

ln 1.09 = t ln 1.016

t = ln 1.09/ln 1.016

t = 5.429 which is approximately 5

So in 2007 + 5 = 2012, the population will be 15 million

8 0

3 years ago