School and Work

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1.) (3x – 2y)^2 =

2.) If x > 2, then x^2– x – 6 over x^2 - 4=

3.) 4 – (-6) over -5 =

4.) If 2x – 3(x + 4) = - 5, then x =

5.) – 3(5 – 6) – 4(2 – 3) =

I know, it's elementary algebra and it's bad I can't even solve 'em, I just don't remember how too!
It's not for homework, it's for a placement test. So any help will do. Thank you!

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Suppose you are standing in the aisle of a bus that travels along a straight road at 100 km/ hr. If you hold a pencil still above your head. Then relative to the bus, the velocity of the pencil is 0 km/ hr, and relative to the road, the pencil has a horizontal velocity of:
a) less than 100 km/ hr
b) 100 km/ hr
c) more than 100 km/ hr

Suppose you release the pencil. While it is dropping, and relative to the road, the pencil still has a horizontal velocity of:
a) less than 100 km/ hr
b) 100 km/ hr
c) more than 100 km/ hr

This means that the pencil will strike the floor at a place directly:
a) behind you
b) at your feel below your hand
c) in front of you

Relative to you, the way the pencil drops
a) is the same as if the bus were at rest
b) depends on the velocity of the bus

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Sorry, I could not read the content fromt this page.

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Sorry, I could not read the content fromt this page.

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Let z = the number of zebras and n = number of neons

then, for 9, z + n = 13 ==> n = 13 - z
also, 2.1z + 1.85n = 25.8 ==> 2.1z +1.85(13 - z) = 25.8
==> z(2.1 - 1.85) = 25.8 - 24.05 ==> 0.25z = 1.75 ==> z/4 = 7/4
==> z = 7 and n = 6

Similarly for the other

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Given the equation: 2 NaClO3 --> 2 NaCl + 3 O2

12 moles of NaClO3 will produce how many grams of O2? How many grams of NaCl are produced when 80 grams of O2 are produced?

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1.Which of the following barium salts should dissolve in a strong acid such as HCl: Ba(OH)2, BaSO4, or BaCO3? Can you explain why please?

2.The cations Ba 2+ and Sr 2+ can be precipitated as very insoluble sulfates.BaSO4 (Ksp = 1.1x 10-10) SrSO4 (Ksp 3.4 x 10-7)

a) If you add sodium sulfate to a solution containing these metal cations, each with a concentration of 0.10 M, which is precipitated first, BaSO4, or SrSO4?

b) What will be the concentration for the first ion that precipitates when the second, more soluble salt begins to precipitate?

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The total weight of an Easter egg is 118 g. This egg consists of a chocolate shell and 17 g of chocolate drops inside the shell.

1. What percentage of the weight of the egg is the chocolate shell?

2. If each chocolate drop weighs 500mg, how many chocolate drops are there inside the egg?

3. If a chocolate drop is melted, its volume is 600mm3. If all of the chocolate drops were melted and placed in a box that is 17cm x 15cm x 18cm, how many chocolate drops would the box hold?

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1. How long should you roast a whole ham that weighs 11 2/3 pounds? Is it.... 2 1/3 hours?
2. At what time should you put the ham in the oven if you want to eat at 5:20 P.M.? Is it ... 3:00 P.M.?

These problems I don't get:
3. How long should you roast a chicken that weighs 3 2/3 pounds?
4. At what time should you put the chicken in the oven if you want to eat at 5:45 P.M.?
5. How long should you roast a pork roast that weighs 3 4/5 pounds?
6. At what time should you put the pork roast in the oven if you want to eat at 6:30 P.M.?

CHART!
Meat--------------------------------Ti… (hour per lb)
Pork Roast-----------------------7/15
Ham--------------------------------1/5
Beef Roast-----------------------1/3
Beef Ribs-------------------------2/5
Chicken---------------------------1 3/4

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14x^3 - 21x

there is a common factor of 7x

7x(2x^2 - 3)

8x^2 - 4x = 4x(2x - 1)

36w^3 - 9w) = 9w(4w^2 - 1) = 9w(2w + 1)(2w - 1)

Check by multiplying.

Read your textbook. Practice. See your teacher---these were very easy !

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MULTI STEP ALGEBRA PROBLEMS HELP PLEASE **** ID APPRECIATE IT..?

9.X+4/-3=6-x

13.7-5x=10-(6x+7)

15.4a+4=3a-4

17.5b-11=13-b

19.-(x+1)=-2(5-x)

21. 6-3a=9-2(2a+5)

23. 3y+2-2y-5=4y+3

25.-(a+3)=-2(2a+1)-7

27..1/2(b-2)=5

29.4x+12=-2(x+3)

31.9x-5=8x-7

33.4x+8/2 =6

35.y-(y+3)=y+6

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Could you please explain these to me?

1. Given the standard free energy of formation values below, calculate the free energy change for this reaction:

?Gf°(H2O2) = -120.4 kJ/mol
?Gf°(H2O) = -237.1 kJ/mol

2. Given the enthalpy change and entropy change values shown below, calculate the free energy change for this reaction at 25°C using the Gibbs free energy equation, ?G = ?H - T?S:

?H°= -196.0 kJ
?S° = 125.7 J/K

3.
Given the enthalpy change and entropy change values below, calculate the free energy change for this reaction at -20°C using the Gibbs free energy equation, ?G = ?H - T?S:

?H°= -196.0 kJ
?S° = 125.7 J/K

Thanks so much!

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Hey please help me on these sums
Working out would be great! Thanks so much

1. Sinenta is making new curtains for her bedroom . The material is 2 metres wide
A) what area of material does she buy?
B) the material costs £5 per metre (square)
How much does her material cost

2. The area of a rectangle is 65cm (square).
The length is 13cm,
What is the length

3. The area of a wall is 48m (square)
The height of the wall is 1.5m.
What is the width?

Thanks so much!! Xxxx

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Actually 1kHz = 1000Hz.
w = c / f
= 3E8m/s / (530E3/s) = 533m
and
= 3E8m/s / (1710E3/s) = 175m

Notice that higher frequencey correlates with shorter wavelength.

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I've been out of math for a while but for #1..use the FOIL method.
F=first
O=outside
I=inside
L=last

(a+2)(a+2)
=a(a)+a(2)+2(a)+2(2)
=a2(squared)+2a+2a+4
=a2+4a+4

I hope I helped! Good luck!

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A Family has built a fence around three sides of their property. In total, they used 550 feet of fencing. By their calculations, the lot is one acre (43,560 square feet). Is this correct? Explain your reasoning.

My teacher gave me a hint and told me that it is a trapezoid land. and the area of the trapezoid is
A=1/2(b1+b2)h

and she gave me additional details:
A=1/2x[x+(550-2x)=43,560

and i still don't know how to solve this.. please show your work :(

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A soil sample has a bulk unit weight of 19.6 kN/m^3 at a water content of 10% and
Gs = 2.7 Determine the void ratio, percentage of air in the voids, and the degree of
saturation of this sample

Answers Given are [ 0.49, 45%, 0.55 (55%)]

I don't know what formulas to use - void ratio is basically the volume of water divided by the volume of solids???

Help will be appreciated greatly.

Thanks

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