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2 years ago

13

Si en un examen 27 preguntas son correctas el 90%, cuántas preguntas son en total?

1 answer:

Nezavi [6.7K]2 years ago

5 0

Respuesta:

30

Explicación paso a paso:

Número total de preguntas = 100%

Número de preguntas correctas = 27

Porcentaje de aciertos = 90%

Por eso,

Si 90% = 27

Luego ; 100% = x

Multiplicar en cruz:

0,9 veces = 27

x = 27 / 0,9

x = 30

Número de preguntas = 30

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3 years ago

Lim x->-5(((1)/(5)+(1)/(x))/(10+2x))=<br><br>correct answer 1/10x = -1/50<br><br>explain:

slava [35]

Given:

The limit problem is:

$lim_{x\to -5}\dfrac{\dfrac{1}{5}+\dfrac{1}{x}}{10+2x}$

To find:

The value of the given limit problem.

Solution:

We have,

$lim_{x\to -5}\dfrac{\dfrac{1}{5}+\dfrac{1}{x}}{10+2x}$

It can be written as:

$=lim_{x\to -5}\dfrac{\dfrac{x+5}{5x}}{2(5+x)}$

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$=lim_{x\to -5}\dfrac{1}{10x}$

Applying limit, we get

$lim_{x\to -5}\dfrac{1}{10x}=\dfrac{1}{10(-5)}$

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2 years ago

There are 2 squares and 8 circles what is the simplest ratio of squares to total shapes

wariber [46]

1:4 is simplest ratio

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2 years ago

Which graph represents the function of f(x) = the quantity of 9 x squared plus 9 x minus 18, all over 3 x plus 6

lora16 [44]

Answer:

The answer is the option C

graph of $3x$ minus $3$ , with discontinuity at negative $2$ , negative $9$

Step-by-step explanation:

we have

$f(x)=\frac{9x^{2}+9x-18}{3x+6}$

Simplify

$f(x)=9\frac{(x^{2}+x-2)}{3(x+2)}$

$f(x)=3\frac{(x^{2}+x-2)}{(x+2)}$

Step 1

Convert to a factored form the numerator

$x^{2}+x-2=0$

Group terms that contain the same variable, and move the constant to the opposite side of the equation

$x^{2}+x=2$

Complete the square. Remember to balance the equation by adding the same constants to each side.

$x^{2}+x+0.25=2+0.25$

$x^{2}+x+0.25=2.25$

Rewrite as perfect squares

$(x+0.5)^{2}=2.25$

Square root both sides

$x+0.5=(+/-)1.5$

$x=-0.5(+/-)1.5$

$x=-0.5+1.5=1$

$x=-0.5-1.5=-2$

so

$x^{2}+x-2=(x-1)(x+2)$

Step 2

Simplify the function f(x)

$f(x)=3\frac{(x^{2}+x-2)}{(x+2)}=3\frac{(x-1)(x+2)}{(x+2)}$

The domain of the function f(x) is all real numbers except the number $x=-2$

Because the denominator can not be zero

$f(x)=3\frac{(x-1)(x+2)}{(x+2)}=3(x-1)=3x-3$

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The discontinuity is at point $(-2,-9)$

the answer in the attached figure

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3 years ago

Read 2 more answers

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svetoff [14.1K]

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Z+5
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Answer: </span>z+5

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3 years ago

Read 2 more answers