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3 years ago

Find an equation in slope-intercept form of the line that has slope –2 and passes through point (1,9)

Mathematics

1 answer:

lozanna [386]3 years ago

8 0

Answer:

y=-2x+11

Step-by-step explanation:

slope intercept form is y=mx+b m being the slope and b the y-intercept

using the slope you can calculate the y intercept

m=-2

y-intercept(b)=11

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during a trip to the supermarket, Jim bought the following items bread $1.45 beans $0.88 toothpaste $2.90 milk $3.55 dog food $6

mr Goodwill [35]

15.28 I think it is the answer bc it said total so u add all the numbers. I added them and it gave me 15.28

5 0

3 years ago

Read 2 more answers

For the graphed exponential equation, calculate the average rate of change from x = −3 to x = 0.

iragen [17]

Answer:

$-\frac{7}{3}$

Step-by-step explanation:

To solve this, we are using the average rate of change formula:

$m=\frac{f(b)-f(a)}{b-a}$

where

$m$ is the average rate of change

$a$ is the first point

$b$ is the second point

$f(a)$ is the function evaluated at the first point

$f(b)$ is the function evaluated at the second point

We want to know the average rate of change of the function $f(x)=0.5^x-6$ form x = -3 to x = 0, so our first point is -3 and our second point is 0. In other words, $a=-3$ and $b=0$ .

Replacing values

$m=\frac{f(b)-f(a)}{b-a}$

$m=\frac{0.5^0-6-(0.5^{-3}-6)}{0-(-3)}$

$m=\frac{1-6-(8-6)}{3}$

$m=\frac{-5-(2)}{3}$

$m=\frac{-5-2}{3}$

$m=\frac{-7}{3}$

$m=-\frac{7}{3}$

We can conclude that the average rate of change of the exponential equation form x = -3 to x = 0 is $-\frac{7}{3}$

4 0

3 years ago

A certain square is to be drawn on a coordinate plane. One of the vertices must be on the origin, and the square is to have an a

Scrat [10]

Answer:

The answer is (C) 8

Step-by-step explanation:

First, let's calculate the length of the side of the square.

$A_{square}=a^2$ , where $a$ is the length of the side. Now, let's try to build the square. First we need to find a point which distance from (0, 0) is 10. For this, we can use the distance formula in the plane:

$d = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}$ which for $x_1=0$ and $y_1 = 0$ transforms as $d=\sqrt{(x_2)^2 + (y_2)^2}$ . The first point we are looking for is connected to the origin and therefore, its components will form a right triangle in which, the Pythagoras theorem holds, see the first attached figure. Then, $x_2$ , $y_2$ and 10 are a Pythagorean triple. From this, $x_2= 6$ or $x_2=8$ while $y_2= 6$ or $y_2=8$ . This leads us with the set of coordinates:

$(\pm 6, \pm 8)$ and $(\pm 8, \pm 6)$ . (A)

The next step is to find the coordinates of points that lie on lines which are perpendicular to the lines that joins the origin of the coordinate system with the set of points given in (A):

Let's do this for the point (6, 8).

The equation of the line that join the point (6, 8) with the origin (0, 0) has the equation $y = mx +n$ , however, we only need to find its slope in order to find a perpendicular line to it. Thus,

$m = \frac{y_2-y_1}{x_2-x_1} \\m = \frac{8-0}{6-0} \\m = 8/6$

Then, a perpendicular line has an slope $m_{\bot} = -\frac{1}{m} = -\frac{6}{8}$ (perpendicularity condition of two lines). With the equation of the slope of the perpendicular line and the given point (6, 8), together with the equation of the distance we can form a system of equations to find the coordinates of two points that lie on this perpendicular line.

$m_{\bot}=\frac{6}{8} = \frac{8-y}{6-x}\\ 6(6-x)+8(8-y)=0$ (1)

$d^2 = \sqrt{(y_o-y)^2+(x_o-x)^2} \\(10)^2=\sqrt{(8-y)^2+(6-x)^2}\\100 = \sqrt{(8-y)^2+(6-x)^2}$ (2)

This system has solutions in the coordinates (-2, 14) and (14, 2). Until here, we have three vertices of the square. Let's now find the fourth one in the same way we found the third one using the point (14,2). A line perpendicular to the line that joins the point (6, 8) and (14, 2) has an slope $m = 8/6$ based on the perpendicularity condition. Thus, we can form the system:

$\frac{8}{6} =\frac{2-y}{14-x} \\8(14-x) - 6(2-y) = 0$ (1)

$100 = \sqrt{(14-x)^2+(2-y)^2}$ (2)

with solution the coordinates (8, -6) and (20, 10). If you draw a line joining the coordinates (0, 0), (6, 8), (14, 2) and (8, -6) you will get one of the squares that fulfill the conditions of the problem. By repeating this process with the coordinates in (A), the following squares are found:

(0, 0), (6, 8), (14, 2), (8, -6)

(0, 0), (8, 6), (14, -2), (6, -8)
(0, 0), (-6, 8), (-14, 2), (-8, -6)
(0, 0), (-8, 6), (-14, -2), (-6, -8)

Now, notice that the equation of distance between the two points separated a distance of 10 has the trivial solution $(\pm10, 0)$ and $(0, \pm10)$ . By combining this points we get the following squares:

(0, 0), (10, 0), (10, 10), (0, 10)
(0, 0), (0, 10), (-10, 10), (-10, 0)
(0, 0), (-10, 0), (-10, -10), (0, -10)
(0, 0), (0, -10), (-10, -10), (10, 0)

See the attached second attached figure. Therefore, 8 squares can be drawn

8 0

3 years ago

Mark is in training for a bicycle race. He needs to ride 50 kilometers a week as part of his training. He rode 18.23 kilometers

Nikitich [7]

Answer:

The answer is B, 17.83 km.

Step-by-step explanation:

To solve this, we need to first find out how many kilometers he rode for both Monday and Wednesday. To do this, add 13.94 and 18.23 together. The answer is 32.17 kilometers. Since we know he has to ride 50 kilometers for the week, we can subtract 32.17 from 50 to find the answer. Note that I didn't attempt to convert 32.17 to kilometers since that was the unit of measure it was already in. Now, after you have done 50-32.17, you will get 17.83. Put this in kilometers. This gives us our answer, which is 17.83 km. Mark needs to ride for 17.83 more kilometers to complete his training for the week.

7 0

2 years ago

The manager of the motor pool wants to know if it costs more to maintain cars that are driven more often. Data are gathered on e

Liula [17]

Answer:

b. There's no statistically significant linear relationship between the number of miles driven and the maintenance cost

Step-by-step explanation:

The p-value for the slope estimate show us how strong is the certainty that there are a linear relationship between both variables. In this case, the p-value for the slopes shows if there is a significant relationship between the number of miles driven and the maintenance cost.

If we have a high p-value like 0.7 we can said that there is no certainty in the linear relationship. it means that there's no statistically significant linear relationship between the number of miles driven and the maintenance cost.

5 0

3 years ago