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2 years ago

What's an expression that represents 5 less than the product of 7 and a number?

Mathematics

1 answer:

Butoxors [25]2 years ago

7 0

Answer:

7x-5

Step-by-step explanation:

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Can someone please answer this question?

Verdich [7]

100 because sum means addition so 1+0+0 is one, and one X one hundred is 100

Hope this helps :D

5 0

3 years ago

What is the answer? Y= -x-4 Y=x

Mashcka [7]

Do you mean like this?

Y = -x - 4
Y = x

x = -x - 4
2x = -4
x = -2

Therefore y = -2

7 0

3 years ago

Let the abbreviation PSLT stand for the percent of the gross family income that goes into paying state and local taxes. Suppose

gavmur [86]

Answer:

Number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.

Step-by-step explanation:

We are given that one wants to estimate the mean PSLT for the population of all families in New York City with gross incomes in the range $35.000 to $40.000.

If sigma equals 2.0, we have to find that how many families should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5.

Here, we will use the concept of Margin of error as the statement "true mean PSLT within 0.5" represents the margin of error we want.

SO, Margin of error formula is given by;

Margin of error = $Z_(_\frac{\alpha}{2}_ ) \times \frac{\sigma}{\sqrt{n} }$

where, $\alpha$ = significance level = 10%

$\sigma$ = standard deviation = 2.0

n = number of families

Now, in the z table the critical value of x at 5% ( $\frac{0.10}{2} = 0.05$ ) level of significance is 1.645.

SO, Margin of error = $Z_(_\frac{\alpha}{2}_ ) \times \frac{\sigma}{\sqrt{n} }$

0.5 = $1.645 \times \frac{2}{\sqrt{n} }$

$\sqrt{n} =\frac{2\times 1.645 }{0.5}$

$\sqrt{n} =6.58$

n = $6.58^{2}$

= 43.3 ≈ 43

Therefore, number of families that should be surveyed if one wants to be 90% sure of being able to estimate the true mean PSLT within 0.5 is at least 43.

4 0

3 years ago

Al oeste de Albuquerque, Nuevo México, la carretera 40 con rumbo al este es recta y tiene una fuerte pendiente hacia la ciudad.

alexgriva [62]

Usando el concepto de pendiente, se encuentra que el cambio en la distancia horizontal es de 10 pies.

La pendiente de una reta es la razón entre el cambio vertical y el cambio horizontal, o sea, cual el cambio vertical cuando el cambio horizontal es de 1.

En este problema, hay que:

La pendiente es -100, o sea, cuando hay un desplazamiento de un pie por adelante, hay una queda de 100 pies.
Bajado 1000 pies, entonces, aplicando la proporción:

1 pie H -> -100 pies V

x pie H -> -1000 pies V

Aplicando la multiplicación cruzada:

$-100x = -1000$