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:

x < 3

Step-by-step explanation:

if the value under the square root sign is negative the result is imaginary.

Answer:

Two real distinct solutions

Step-by-step explanation:

Hi there!

Background of the Discriminant

The discriminant [tex]b^2-4ac[/tex] applies to quadratic equations when they are organised in standard form: [tex]ax^2+bx+c=0[/tex].

All quadratic equations can be solved with the quadratic formula: [tex]x=\frac{-b\pm\sqrt{b^2-4ac} }{2a}[/tex].

When [tex]b^2-4ac[/tex] is positive, it is possible to take its square root and end up with two real, distinct values of x.

When it is zero, we won't be taking the square root at all and we will end up with two real solutions that are equal, or just one solution.

When it is negative, it is impossible to take the square root and we will end up with two non-real solutions.

Solving the Problem

[tex]0=-2x^2+3[/tex]

We are given above equation. Notice how there are values for a and c but none for b, as there is no bx term. This means that the value of b is 0. We can rewrite the equation so it shows this:

[tex]0=-2x^2+0x+3[/tex]

Now that we have the values of a, b and c, we can plug them into the discriminant:

[tex]D=0^2-4(-2)(3)\\D=-4(-2)(3)\\D=-4(-6)\\D=24[/tex]

Because 24 is positive, there are two real, distinct solutions for this equation.

I hope this helps!

Answer: A

Step-by-step explanation:

Each gallon costs 3 dollars.

8(gallons) times $3(for each gallon) = 24(dollars).

Answer:

5,1

Step-by-step explanation:

x= tan27⁰ x 10 ≈ 5,1

.....

Answer:

b or c or 5.1

Step-by-step explanation:

The basic trig identity that does not involve the hypotenuse is the Tan(theta).

Tan(theta) = opposite / adjacent. That definition applies only to a right triangle. It has to be modified if the triangle is some other kind.

The opposite side is the one not making up the reference angle (x in this case).

The adjacent side is the one making up the angle that is not the hypotenuse.

opposite side = x

adjacent side = 10

theta = 27 degrees.

Tan(theta) = opposite / adjacent

Tan(27) = x / 10

Tan(27) = 0.5095

0.5095 = x / 10               Multiply by 10

10*0.5095 = x

x = 5.095

It rounds to 5.1

No one except the answer key can know whether to choose b or c.

Divide capacity by sections:

5782 / 24 = 240.9167

The number of seats in each section is needs to be a whole number so there are 240 seats per section:

240 seats per section x 24 sections = 5,760 seats.

Priority seats is capacity - total section seats:

5782 - 5760 = 22

There are 22 priority seats

Answer:

49

Step-by-step explanation:

Seven times seven (7x7) equals forty-nine

Answer:

The answer is forty nine (49)

Answer:

P - Q = - 11b² + 8b - 4

Step-by-step explanation:

P - Q

= - 4b² + 6b - 9 - (7b² - 2b - 5) ← distribute parenthesis by - 1

= - 4b² + 6b - 9 - 7b² + 2b + 5 ← collect like terms

= - 11b² + 8b - 4

Answer:

[tex]y = \frac{3}{2}x +2[/tex]

Hope this helps!

Step-by-step explanation:

so for this one u do

[tex]15 \times 9 + 9 \times 4 + 15 \times 4[/tex]

231 the times it by 2 for the both sides

231×2=462 cm2

hope this make sense :)

Answer:

D

Step-by-step explanation:

answer:

20 out of 798

Step-by-step explanation:

6x4=20

Answer:

?

Step-by-step explanation:

Answer: 0.43ft²

Step-by-step explanation:

You didn't really specify part A but In assuming that the question you posted is part A. Anyways in this case, area will be calculated by multiplying the length by the width.

Since the piece of wood has a length that is 2.45 feet and width that is 2.097 inches, then the area will be:

= 2.45 × 0.17475

= 0.4281375 ft²

= 0.43ft² to nearest hundredths

Note 1 foot = 12 inches

Therefore, 2.097 inches = 2.097/12 = 0.17475 feet

Hope this help!!!

Have a nice day!!!

Answer:

that gy is rong dount do it

Step-by-step explanation:

Answer:

Bases change red litmus into blue and bases have a slippery and soapy texture. Therefore, we can conclude that out of the given options, one way to test whether an unknown solution is acidic or basic is to check whether the solution has a slippery feel

Step-by-step explanation:

Answer:

3000 Meters?

Step-by-step explanation:

I say the question mark because kilo quite literally just means 1000. If she ran 3 of these sets of Kilometers, that would be 3000.

Answer:

3000 meter hope this helps

Answer:

12 3/5 pi

Step-by-step explanation:

First find the area of the circle

A = pi r^2

A = pi ^^2

A = 36 pi

Then find the fraction of the circle that is shaded

A circle is 360 degrees

126/360 =7/20

Multiply the area by the fraction

7/20 * 36 pi

63/5 pi

12 3/5 pi

Answer:

the area of sector is

[tex] \frac{126}{360} \times \pi \times 6 {}^{2} = \frac{63}{5} \pi[/tex]

Answer:

option 1

Step-by-step explanation:

[tex]Area = \frac{3}{4} \times \frac{5}{6} = \frac{15}{24}[/tex]

Answer:

The ASAP Math program provides an opportunity for additional small group instruction for students who find the math program challenging. Students in grades 1 to 4 will come to the ASAP room two to three times a week during the math block.

Step-by-step explanation:

Answer:

Area of  shaded region = 134.13 square feet

Step-by-step explanation:

Area of the shaded region = Area of square - Area of circle

                                         [tex]= ( 25 \times 25) - ( \pi 12.5^2)\\= 625 - 490.87\\= 134.13 ft^2[/tex]

Answer:

A. 2sqrt3

Step-by-step explanation:

Hope this helps!

Answer:

Acute angled and scalene because if the sum of two angles is 110 then the third angle should be 70 which is acute angle

Answer:

V=864 cubic feet

Step-by-step explanation:

Volume of a rectangular prism is Length x width x depth

So V=12x8x9

V=864 Cubic feet

Answer:

x = 2.69 or x = -0.19

Step-by-step explanation:

Given:

2x² − 5x − 1 = 0

x = {-b ± √b² - 4ac} / 2a

a = 2

b = -5

c = -1

x = {-b ± √b² - 4ac} / 2a

= {-(-5) ± √(-5)² - 4(2)(-1)} / 2 * 2

= {5 ± √25 - (-8)} / 4

= {5 ± √25 + 8} / 4

= 5 ± √33 / 4

= 5 ± 5.75 /4

x = 5/4 + 5.75/4 or x = 5/4 - 5.75/4

x = 10.75/4 or x = -0.75/4

x = 2.69 or x = -0.19

Answer:

71. 8

Step-by-step explanation:

volume of a cylinder = 4/ 3 π r² h

=> 4817 = 4/ 3 × 22/ 7 × 4² × h

=> h = (4817 × 3 × 7)/ (4 × 22 × 4²)

=> h = 71.8

Answer:

D

Step-by-step explanation:

by subtraction of these 2 equation,

2p = 2

p = 1

Answer:

0.3 if you typed the calculating correctly.

because then all operations are of the same priority and ranking, and we go simply from left to right :

0.5/0.5 = 1

and then there is 1 × 0.3 = 0.3

but if you missed to write any brackets like for

0.5/(0.5 × 0.3)

then this goes differently, because now 0.3 is in the bottom part of the division/quotient.

we can still shorten the expression, as the 0.5 on top and on the bottom eliminate each other to 1. but it leaves us with

1/0.3

now, what is 0.3 ?

it is actually 3/10.

so, we have 1/(3/10) which is the same as

(1/1) / (3/10)

to solve this, the two inner numbers of the quotient multiply and the two outer numbers multiply giving us

(1×10) / (1×3) = 10 / 3 = 3.33333...

so, please pick the solution that best fits your actual question.

Answer:

There isnt a graph.

Step-by-step explanation:

Answer:632 ft²

Step-by-step explanation: