EXERCISE 22.2A
1 A heater uses 3 units of electricity in 40 minutes.
How many units does it use in 2 hours?
2 A machine prints 1500 newspapers in 45 minutes.
How many does it print in 12 hours?
3 A bricklayer lays 1200 bricks in an average 8-hour day.
How many bricks does he lay in a 40-hour week?
4 A combine harvester produces 9 tonnes of grain in 6 hours.
How many tonnes does it produce in 54 hours?
5 A machine puts tar on a road at the rate of 4 metres in 5 minutes.
a) How long does it take to cover 1 km of road?
b) How many metres of road does it cover in 8 hours?
181

Answer:

11  1.6

12  Mauricio

Step-by-step explanation:

11.  Take the absolute value of each number to determine which is furthest from zero

|-1.5| and |1.6|

1.5  and 1.6

1.6 is greater than 1.6  so it is further from 0

12.  The fastest time is the smallest time

The ones place all has 7's so look at the tenths place

The smallest number will have the fastest time

Mauricio has a 2 which is the smallest number

Mauricio has the fastest time

Answer:

5x+8

Step-by-step explanation:

Answer:5x+8

Step-by-step explanation:

8x+13

-3x

5x+13

-5

5x+8

Answer:

La población 20 horas después será de 321,161 bacterias.

Step-by-step explanation:

t horas después de iniciar la observación, tiene una razón de cambio de P'(t) = 350 e0.18t + 220 e-0.3t.

Esto implica que la población después de t horas viene dada por:

[tex]P(t) = \int P^{\prime}(t) dt[/tex]

[tex]P(t) = \int (350e^{0.18t} + 220e^{-0.3t}) dt[/tex]

Teniendo en cuenta que

[tex]\int e^{at} dt = \frac{1}{a}e^{at}[/tex]

[tex]P(t) = \int (350e^{0.18t} + 220e^{-0.3t}) dt[/tex]

[tex]P(t) = \frac{350}{0.18}e^{0.18t} - \frac{220}{0.3}e^{-0.3t} + K[/tex]

En que k es la población inicial, o sea, [tex]K = 250000[/tex]. Entonces

[tex]P(t) = 1944.44e^{0.18t} -733.33e^{-0.3t} + 250000[/tex]

¿Cuál será la población 20 horas después?

Esto eres P(20). Entonces:

[tex]P(20) = 1944.44e^{0.18*20} -733.33e^{-0.3*20} + 250000 = 321161[/tex]

La población 20 horas después será de 321,161 bacterias.

Answer:

3,2

Step-by-step explanation:

Answer:

(3,1)

Step-by-step explanation:

If you moved two units left you would be at (3,2) the move one down you would be at (3,1)

Answer:

(x+1)² = 14

a = 1, b = 14

Step-by-step explanation:

Given the equation, x² + 2x = 13

We are to use the completing the square method to express in the form

(x + a)² = b

x² + 2x = 13

Add the square of half of the coefficient of x to both sides

Coefficient of x = 2

Half of the coefficient of x = 2/2

Square of the result = (2/2)²

Square of the result = 1²

Add (1/2)² to both sides

x² + 2x + (1)² = 13 + (1)²

(x+1)² = 13 + 1

(x+1)² = 14

Compare with  (x+a)² = b

a = 1 and b = 14

3m^2 +5m-2-2m+18

3m^2 +3m+16

Answer:

3m² + 3 m + 16

Step-by-step explanation:

( 3 m ² + 5 m - 2 ) + ( - 2m + 18 )

Remove the unnecessary parantheses and rewrite

3 m ² + 5 m - 2 - 2 m + 18

combine like terms

3m² + 5 m - 2 m + 18 - 2

calculate the sum

3m² + 3 m + 16

Answer:

56

Step-by-step explanation:

To find the "consequent," write out and solve an equation of ratios:

  3         x

------- = ------

  8         21

Through cross-multiplication, this yields  8x = 63, so that x must be x = 63/8.

Alternatively, solve this modified version of the original equation for x:

  3         21

------- = ------

  8          x

Then 3x = 8(21), or x = 8(7), or x = 56.

Note that 21 and 56 are in the ratio 3:8

Step-by-step explanation:

a) 2z+3z+4z=180

9z=180

z=20

So,three angles are 40,60 and 80

b) (y+30)+(2y+80)+(y+10)=180

y+30+2y+80+y+10=180

4y+120=180

4y=60

y=15

Three angles are 45,110,25

Answer:

B

Step-by-step explanation:

2+5/2 is hard to add since first you have to make 2 into a fraction with the denominator 2. If you use the associative property, you can just easily combine -1/2 and 5/2 without any converting into fractions

Answer: it b y’all

Step-by-step explanation: I took the test

Answer:

B

Step-by-step explanation:

To determine the maxima and minima of the polynomial, differentiate the given based on x and equate to 0.                                   C(x) = 400x - 0.2x²                               dC(x) / dt = 400 - 0.4 x = 0 The value of x is 1000. This is the value of the maxima. As the value of C(x) continously becomes lesser as the value of x is set higher, the minima is not identified. Substitute x to the original equation,                               C(x) = (400)(1000) - 0.2(1000²) = $ 200,000Thus, the answer is letter B. 

Answer:

In order to make the maximum profit, the company should sell each widget at (the currency isn't given, so I'll be assuming USD) $36.

Step-by-step explanation:

The amount of profit y made by the company from selling each widget at x price is modeled by the equation:

[tex]y=-x^2+72x-458[/tex]

Since this is a quadratic with a negative leading coefficient, its maximum will occur at its vertex point. We want to find the price that the widget should be sold to make the maximum profit. So, we want to find the x-coordinate of the vertex. This is given by the formula:

[tex]\displaystyle x=-\frac{b}{2a}[/tex]

In this case, a = -1, b = 72, and c = -458. Substitute and evaluate:

[tex]\displaystyle x=-\frac{72}{2(-1)}=36[/tex]

In order to make the maximum profit, the company should sell each widget at (the currency isn't given, so I'll be assuming USD) $36.

Answer:

Step-by-step explanation:

You can't see the picture really well

Given:

The terminal point of [tex]\phi[/tex] is (1,0).

To find:

The value of [tex]\tan\phi[/tex].

Solution:

If the terminal point of [tex]\theta [/tex] is (x,y), then

[tex]\tan \theta=\dfrac{y}{x}[/tex]

It is given that the terminal point of [tex]\phi[/tex] is (1,0).

Here, x-coordinate is 1 and the y-coordinate is 0. Using the above formula, we get

[tex]\tan \phi=\dfrac{0}{1}[/tex]

[tex]\tan \phi=0[/tex]

Therefore, the value of [tex]\tan \phi[/tex] is 0.

Answer: 237,500 total decrease

Step-by-step explanation:

Answer:

33

Step-by-step explanation:

The formula for solving the area of a Trapezoid is a+b/2*h if we substitute the value to 16+3/2*3 it will equal 33

Step-by-step explanation:

AAA are the correct answer.

It is related to congurency.

Answer:

AAA

Step-by-step explanation:

You have 2 of angles. Add them together and subtract them by 180. That is how to got AAA.

Answer:

x = 60°

Step-by-step explanation:

∠ CGE = ∠ FGD = 30° ( vertical angles )

∠ CGB = 90° , then

x + 30° = 90° ( subtract 30° from both sides )

x = 60°

Answer:

I think it is 4

I am not sure about it

9x²-24xy+16y²

(3x)²-2.(3x)(4y) +(4y)²

(3x-4y)²

(3x-4y)(3x-4y)

Answer:

[tex](3x -4y)^2[/tex]

Step-by-step explanation:

[tex]9x^2 - 24xy + 16y^2 = (3x)^2 - 24xy + (4y)^2[/tex]

                           [tex]=(3x)^2 -2(3x \times 4y) + (4y)^2\\[/tex]

a = 3x , b = 4y . The expression [tex]a^2 - 2ab + b^2 = (a-b)(a-b) =(a-b)^2[/tex]

                           [tex]=(3x -4y)(3x - 4y)[/tex]

[tex]9x^2 - 24xy + 16y^2 = (3x -4y)^2[/tex]

Answer:

A = (1/2 x b x h ) 4 + l^2

= 1/2 x 5 x 8 x4 + 5 x 5

80 + 25

= D. 105 cm2

Answer:

105

Step-by-step explanation:

Answer:

This doesn't make sense because there is no C variable, but I will solve for f if that helps.

Step-by-step explanation:

[tex]f=1.80+32[/tex]

       [tex]-32[/tex]   [tex]-32[/tex]          

[tex]f=-30.2[/tex]      

Answer:

The answer is25th August

Answer:

I think it is the first one i think

Step-by-step explanation:

Answer:

-6 and 11

Step-by-step explanation:

The only factors of 66 are 11, 6, 2 and 3

11*6 is the only pair whose product is 66

The difference betwen 11 and 6 is 5

11 must be positive and 6 negative since the sum is positve

Answer:

A

Step-by-step explanation:

Desnity: mass/volume

3/20= .15

Answer:

ans: 31°

Step-by-step explanation:

<EFG = <EFH + <HFG

2x+52= 21 + ( x+31)

2x-x= 21 +31 -52

x= 0

so our question is to find <HFG so,

x+31°= 31°