Witch expression is equivalent to (-4y-x)-3y-9x)

As you can see I keep getting questions wrong.... Can you answer the last question?

aivan3 [116]

Answer:

y = 0

Step-by-step explanation:

It is always a good idea to look at the question and make some observations about it. Here, you might observe ...

all of the bases are powers of 3: 243 = 3^5; 9 = 3^2
y is a factor of every exponent

The latter observation is important, because it means that when y=0, every exponential expression has a value of 1. Hence y = 0 is a solution.

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To solve the equation, you can write it in terms of powers of 3.

(3^5)^(-y) = (3^-5)^(3y)·(3^2)^(-2y)

3^(-5y) = 3^(-15y)·3^(-4y)

3^(-5y) = 3^(-19y)

-5y = -19y . . . . . . . . equating exponents; equivalent to taking log base 3

14y = 0 . . . . . . . . . . add 19y

y = 0 . . . . . . . . . . . one solution

______

The rules of exponents we used are ...

(a^b)(a^c) = a^(b+c)

(a^b)^c = a^(bc)

1/a^b = a^-b

4 0

2 years ago

"Data from the World Health Organization in 2013 were used to predict the life expectancy of men in a country from the life expe

marshall27 [118]

Answer:

The predicted life expectancy of men in a country in which the life expectancy of women is 70 years is 65.33 years.

Step-by-step explanation:

The least square regression line is used to predict the value of the dependent variable from an independent variable.

The general form of a least square regression line is:

$\hat y=\alpha +\beta x$

Here,

y = dependent variable

x = independent variable

α = intercept

β = slope

The regression line to predict the life expectancy of men in a country from the life expectancy of women in that country is:

$\hat y=3.73 +0.88 x$

Compute the life expectancy of men in a country in which the life expectancy of women is 70 years as follows:

$\hat y=3.73 +0.88 x$

$=3.73 +(0.88\times 70)\\=3.73+61.6\\=65.33$

Thus, the predicted life expectancy of men in a country in which the life expectancy of women is 70 years is 65.33 years.

6 0

3 years ago

Martin is interested in the effects of different kinds of instruction on videogame performance. Martin asks 30 college freshmen

777dan777 [17]

Answer:

Between - groups variance

Step-by-step explanation:

From the question we see that the college freshmen are assigned to one of the three given groups. This means that they are exposed to different experimental conditions and thus it means that the variation differs as a result of different experimental conditions between the groups.

Thus, these differences reflect between - group variance.

5 0

2 years ago

Write the linear inequality shown in the graph.

Korolek [52]

Fist, in the equation y=mx+b, b is the y-intercept. The y-intercept is the poin on the line that crosses the x-axis; the y-intercept is the value of yThese equations follow that format.
Y=mx+b
y $\geq$ 3x-4. <-----In this equation, the slope(m)=3 b= -4.

On the graph, we can see that the line crosses the x-axis at y=-4. Knowing that, we can eliminate the answer choices with +4 in the inequality.

The next step, is to pick an (x,y) coordinate that is in the shaded region and plug it into the remaining 2 inequalities. Which ever inequality is true after you solve it, that is the correct answer.
For example, I'll choose to plug in (-4,4) into the y $\geq$ 3x-4.
y $\geq$ 3x-4.
(4) $\geq$ (3(-4))-4.
(4) $\geq$ (-12)-4.
(4) $\geq$ -16

So, this statement is true becasue -16 is less than positive 4. Therefore, the correct answer would be y $\geq$ 3x-4. Hope that helped! Comment back with any further questions!

6 0

2 years ago

Given ƒ(x) = 3x + 9, find x when ƒ(x) = 21.

Dima020 [189]

3x + 9 = 21
3x = 12
x = 4

7 0

2 years ago

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