Graph the line passing through (1,2) whose slope m= -1/3

A rectangular driveway has an area of 880 square feet and a perimeter of 128 feet. What are the dimensions of the driveway?

mamaluj [8]

Answer:

Dimensions are 20 X 44 feet

Step-by-step explanation:

First we need to build two equations:

For area X times Y = 880

For Perimeter 2x + 2y = 128

Now we need to solve one so we can substitute it into the other:

2x + 2y = 128 becomes

2x = 128 - 2y and then

x = 64 - y We will substitute this into the are equation

(64 - y)y = 880

64y - $y^{2}$ = 880

- $y^{2} + 64y -880 = 0$

factor out the negative

-( $y^{2} - 64y +880 = 0$

Factor:

-(y - 20)(y - 44) = 0

y-20 = 0 and y - 44 = 0

y = 20 and y = 44

Plugging these in two both of our formulas works

20 X 44 = 880 for area

2(20) + 2 (44) = 128 for perimeter

8 0

3 years ago

Sally gets a cup of coffee and a muffin every day for breakfast from one of the many coffee shops in her neighborhood. She picks

aniked [119]

Answer:

A. Mean of the amount Sally spends on breakfast daily = $ 3.90

Standard deviation of the amount Sally spends on breakfast daily = $ 0.34 (rounding to the next cent)

B. Mean of the amount Sally spends on breakfast weekly = $ 27.30

Standard deviation of the amount Sally spends on breakfast weekly = $ 0.89 (rounding to the next cent)

Step-by-step explanation:

1. Let's review the information given to us to answer the question correctly:

Average price of a cup of coffee = $ 1.40

Standard deviation = $0.30

Average price of a muffin = $ 2.50

Standard deviation = $ 0.15

The two prices are independent of each other

2. What is the mean and standard deviation of the amount Sally spends on breakfast daily?

Let's recall that:

1. The mean of the sum of two independent variables is the sum of their means.

2. The variance of the sum of two independent variables is equal to the sum of their variances.

Therefore,

Mean of the amount Sally spends on breakfast daily = Average price of a cup of coffee + Average price of a muffin

Replacing with the values we know:

Mean of the amount Sally spends on breakfast daily = 1.40 + 2.50

Mean of the amount Sally spends on breakfast daily = $ 3.90

Variance of the amount Sally spends on breakfast daily = Variance of the price of a cup of coffee + Variance of the price of a muffin

Replacing with the values we know:

Variance of the amount Sally spends on breakfast daily = 0.30² + 0.15²

Variance of the amount Sally spends on breakfast daily = 0.1125

Standard deviation of the amount Sally spends on breakfast daily = √0.1125

Standard deviation of the amount Sally spends on breakfast daily = $ 0.34 (rounding to the next cent)

3. What is the mean and standard deviation of the amount she spends on breakfast weekly (7 days)?

Mean of the amount Sally spends on breakfast weekly = 7 * Mean of the amount Sally spends on breakfast daily

Mean of the amount Sally spends on breakfast weekly = 7 * 3.90

Mean of the amount Sally spends on breakfast weekly = $ 27.30

Variance of the amount Sally spends on breakfast weekly = 7 * Variance of the amount Sally spends on breakfast daily

Variance of the amount Sally spends on breakfast weekly = 7 * 0.1125

Variance of the amount Sally spends on breakfast weekly = 0.7875

Standard deviation of the amount Sally spends on breakfast weekly = √0.7875

Standard deviation of the amount Sally spends on breakfast weekly = $ 0.89 (rounding to the next cent)

3 0

3 years ago

find four consecutive even integers such that the sum of the third and fourth is 6 less than four times the first

lisabon 2012 [21]

Answer:

The numbers are 2, 4, 6 and 8

Step-by-step explanation:

let the four numbers be x, y, z and l respectively

then:

x+y+z+l

(z+l)–6=4x

since they are all four consecutive even integers

then y=x+2

z=y+2=x+4

l=z+2=x+6

since (z+l)–6=4x

then ((x+4)+(x+6))–6=4x

2x+4=4x

4=4x–2x

4=2x

2=x

5 0

3 years ago

A bunch of seedless black grapes costs $2.00. How many can you buy for $20.00?

MAVERICK [17]

10 of themyou can buy

7 0

3 years ago

Read 2 more answers

In geometry, how do defined terms and undefined terms relate to each other?

mart [117]

In geometry, definitions are formed using known words or terms to describe a new word. There are three words in geometry that are not formally defined. These three undefined terms are point, line and plane.

POINT (an undefined term) 
In geometry, a point has no dimension (actual size). Even though we represent a point with a dot, the point has no length, width, or thickness. A point is usually named with a capital letter. In the coordinate plane, a point is named by an ordered pair, (x,y). 

LINE (an undefined term) 
In geometry, a line has no thickness but its length extends in one dimension and goes on forever in both directions. A line is depicted to be a straight line with two arrowheads indicating that the line extends without end in two directions. A line is named by a single lowercase written letter or by two points on the line with an arrow drawn above them. 

PLANE (an undefined term) 
In geometry, a plane has no thickness but extends indefinitely in all directions. Planes are usually represented by a shape that looks like a tabletop or wall. Even though the diagram of a plane has edges, you must remember that the plane has no boundaries. A plane is named by a single letter (plane m) or by three non-collinear points (plane ABC). 

Undefined terms can be combined to define other terms. Noncollinear points, for example, are points that do not lie on the same line. A line segment is the portion of a line that includes two particular points and all points that lie between them, while a ray is the portion of a line that includes a particular point, called the end point, and all points extending infinitely to one side of the end point. 

Defined terms can be combined with each other and with undefined terms to define still more terms. An angle, for example, is a combination of two different rays or line segments that share a single end point. Similarly, a triangle is composed of three noncollinear points and the line segments that lie between them. 

Everything else builds on these and adds more information to this base. Those added things include all the theorems and other "defined" terms like parallelogram or acute angle.

8 0

3 years ago