what is energy efficiency

Answer:

Step-by-step explanation:

P = 90

r = 40% = 40/100 = 0.4

t = 3 years

It is not clear to me what this means. Is the 40% for each year for 3 years or is the interest rate = 40% period. I know that in some of the poorer countries, this is not an unusual amount to pay for each year he holds the loan.

I will take it as 40% for each year for 3 years.

i = prt = 90 * 0.4 * 3

i = 108

Answer:

is there a pic to go along? i need more to this..

Answer:

The directional derivative of f at A in the direction of [tex]\vec{u}[/tex] AD is 7.

Step-by-step explanation:

Step 1:

Directional of a function f in direction of the unit vector [tex]\vec{u}=(a,b)[/tex] is denoted by [tex]D\vec{u}f(x,y)[/tex],

[tex]D\vec{u}f(x,y)=f_{x}\left ( x ,y\right ).a+f_{y}(x,y).b[/tex].

Now the given points are

[tex]A(8,9),B(10,9),C(8,10) and D(11,13)[/tex],

Step 2:

The vectors are given as

AB = (10-8, 9-9),the direction is

[tex]\vec{u}_{AB} = \frac{AB}{\left \| AB \right \|}=(1,0)[/tex]

AC=(8-8,10-9), the direction is

[tex]\vec{u}_{AC} = \frac{AC}{\left \| AC \right \|}=(0,1)[/tex]

AC=(11-8,13-9), the direction is

[tex]\vec{u}_{AD} = \frac{AD}{\left \| AD \right \|}=\left (\frac{3}{5},\frac{4}{5} \right )[/tex]

Step 3:

The given directional derivative of f at A [tex]\vec{u}_{AB}[/tex] is 9,

[tex]D\vec{u}_{AB}f=f_{x} \cdot 1 + f_{y}\cdot 0\\f_{x} =9[/tex]

The given directional derivative of f at A [tex]\vec{u}_{AC}[/tex] is 2,

[tex]D\vec{u}_{AB}f=f_{x} \cdot 0 + f_{y}\cdot 1\\f_{y} =2[/tex]

The given directional derivative of f at A [tex]\vec{u}_{AD}[/tex] is

[tex]D\vec{u}_{AD}f=f_{x} \cdot \frac{3}{5} + f_{y}\cdot \frac{4}{5}[/tex]

[tex]D\vec{u}_{AD}f=9 \cdot \frac{3}{5} + 2\cdot \frac{4}{5}[/tex]

[tex]D\vec{u}_{AD}f= \frac{27+8}{5} =7[/tex]

The directional derivative of f at A in the direction of  [tex]\vec{u}_{AD}[/tex] is  7.

Answer:

JM = 18 units

Step-by-step explanation:

∆MHN and ∆JKH are similar (by A.A.A axiom)

so, their sides are proportional

i.e.

(JM+18)/(20+15) = 18/15

or, JM + 18 = 540/15

or, JM = 36-18

hence, JM = 18

Answer:

There are no like terms.

Step-by-step explanation:

Answer:

No. of sweets = 123

No. of children = 7

then

sweets per children =123/7 =17. 57

Answer: =17.57

Step-by-step explanation:

Divide the no. of sweets by the no. of children

=123/7

=17.57

Answer:

= -2/7

Step-by-step explanation:

We can use the slope formula

m = (y2-y1)/(x2-x1)

    = ( 6-14)/(13 - -15)

    = (6-14)/(13+15)

    = -8/28

   = -2/7

Answer:

1000 cm

Step-by-step explanation:

Recall that 100 cm = 1 m.

This results in the conversion factor    100cm

                                                              -------------

                                                                   1 m

Then 10 m times the conversion factor shown above yields 1000 cm

Answer:

5 shirts

Step-by-step explanation:

Y=12x+3 equation 1

y=8x+23 equation 2

12x+3=8x+23 substituting y value will cause equations to equal

4x=20

x=5 shirts

check answer

y=12x+3

y=12(5)+3

y=60+3

y=63

y=8x+23

y=8(5)+23

y=40+23

y=63

Answer:

21

Step-by-step explanation:

If lines m and n are equal, line t intersects both of them at the exact same angle. This means that 6x+3=7x-19. Start moving the variables to one side. 3=x-19. Then move the numbers to the other side of the equation. x=21.

Answer:

45kg

Step-by-step explanation:

60.3/4=45

Answer:

32ft

Step-by-step explanation:

Tan = opp/adj

Tan(65) = n / 15

Tan(65) x 15 = n

n = 32.16 = 32ft

Answer:

32 feet

Step-by-step explanation:

Hi there!

We are given a right triangle and the angle of elevation (one of the acute angles in the triangle) as 65°, as well as one of the legs (sides that make up the right triangle) as 15

We need to find the height of the triangle.

Let's make the height of the triangle (the side we need to find) x

Since we need to find the height of the triangle, let's use tangent. As we have the angle of elevation given, we'll use that.

Recall that tangent is [tex]\frac{opposite}{adjacent}[/tex]

in reference to the angle of elevation, the opposite side is x, and the adjacent side is 15

that means that:

tan(65)=[tex]\frac{x}{15}[/tex]

plug tan(65) into your calculator (make sure it's on degree mode!)

tan(65)≈2.14

2.14=[tex]\frac{x}{15}[/tex]

multiply both sides by 15 to clear the fraction

32.1=x

The problem asks us to round to the nearest foot, so the height of the building is 32 feet

Hope this helps! :)

Answer:

m = w - t

£108

Step-by-step explanation:

m = Money Billy has to spend per week :

m = wage, w - tax, t

Hence,

m = w - t

Given;

Wage = £150 ; tax = £42

m = £150 - £42

m = £108

Answer:

[tex]x^4+2x^3+2x^2+2x+1[/tex]

Step-by-step explanation:

Given that,

[tex](x+1)^2 . (x^2+1) = 0[/tex]

We know that, [tex](a+b)^2=a^2+b^2+2ab[/tex]

So,

[tex](x+1)^2=x^2+1+2x[/tex]

So,

[tex](x+1)^2 . (x^2+1) = (x^2+1+2x)(x^2+1)\\\\=x^2\times x^2+x^2+2x^3+x^2+1+2x\\\\=x^4+2x^3+2x^2+2x+1[/tex]

So, the value of the given expression is equal to[tex]x^4+2x^3+2x^2+2x+1[/tex]

Answer:

A. 3.60+5/6x=4.35  

Step-by-step explanation:

Total cost = milk + price per pound of oranges* number of pounds  

We know the total cost = 4.35 and the cost of the milk = 3.60  and the number of pounds of oranges = 5/6  

4.35 = 3.6 +5/6 * x

Answer:

a

Step-by-step explanation:

Answer:

g = 7

Step-by-step explanation:

3g - 4 = 17

+ 4 + 4

3g = 21

÷3 ÷3

g = 7

Answer:

g=7

Step-by-step explanation:

First add 17+4=21 to find out how much 3g needs to equal. 3g needs to get to 21. Next, do 21/3=7. g=7

Hope this helps!

Answer:

3.16666667 tons

Step-by-step explanation:

hope this helps have a good evening

Answer:

The number which is more than 6 and less than 8 is 7.

Step-by-step explanation:

There are the natural numbers.

To find the number which is more than 6 but less than 8.

The numbers which are more than 6 are 7, 8, 9, 10, ....

The numbers which are less than 8 are ...,3, 4, 5, 6, 7

So, the number which is more than 6 and less than 8 is 7.

Answer:

10 pounds

Step-by-step explanation:

165 ounces = 10 pounds

Answer:

10 pounds, 5 ounces

Step-by-step explanation:

The phrasing of the question is unclear. 165 ounces is itself a measure of weight, but it can be further broken down into pounds and ounces.

Recall that 1 pound = 16 ounces. Therefore, 165 ounces = 10 pounds with remainder of 5 ounces. Or in simple decimals it is 165 ounces / 16 ounces = 10.3125 pounds.

Answer:

pls dont kill my dad.. i cant help but please. hes the only thing i have left man

Step-by-step explanation:

i would so help if i could but i just really dont want shrek dead

Answer:

4cm

Step-by-step explanation:

first find the length of the side of one square

the length of the rectangle will be twice the width

let y represent the width

area of a rectangle=length x width

2cm²=2yxy

2cm²=2y²

2cm²/2=2y²/2

1cm²=y²

1√cm²=√y²

1cm=y

perimeter of a square=4xside

4x1cm

4cm

Answer: c

Step-by-step explanation:

In order to be parallel, the slope must be the same. This means slope is 2

Now one of the point is 5,-1, so do 2x5 + x = -1, so x = -11

meaning b is -11

so the equation should be y=2x-11

Answer:

Step-by-step explanation:

52 + 27 = angle 1 (sum of two interior opposite angle is equal to the exterior angle formed)

79 = angle 1

angle 2 + 71 = 92 degree (sum of two interior opposite angle is equal to the exterior angle formed)

angle 2 = 92 - 71

angle 2 = 21 degree