All Answers

Melody:
What kind of calculator are you using.
-8^(1/3) works fine on my calculator.

What is sqrt(-8,3) looks like the input for some computer language,it is not standard maths notation.

I'm using the web2.0calc.com scientific calculator.
Did you tried to input -8^(1/3) and pressed Enter or on = symbol?

The return is:

pmatenseOct 2, 2013

+118725

I'm not intending to do the question but these are the properties that your teacher is referring to. I copied them from http://www.aaamath.com/pro74ax2.htm

There are four mathematical properties which involve addition. The properties are the commutative, associative, additive identity and distributive properties.

Commutative property: When two numbers are added, the sum is the same regardless of the order of the addends. For example 4 + 2 = 2 + 4

Associative Property: When three or more numbers are added, the sum is the same regardless of the grouping of the addends. For example (2 + 3) + 4 = 2 + (3 + 4)

Additive Identity Property: The sum of any number and zero is the original number. For example 5 + 0 = 5.

Distributive property: The sum of two numbers times a third number is equal to the sum of each addend times the third number. For example 4 * (6 + 3) = 4*6 + 4*3

MelodyOct 2, 2013

+118725

I have no idea what you are talking about.

MelodyOct 2, 2013

+118725

1mm on the map = 62500mm in real life
so
175mm on the map = 62500mm * 175 in real life = 10937500mm
There are 1000mm in a metre so
10937500/1000 = 10937.5m
so X = 10937.5

alternatively

1mm on the map = 62500mm in real life = 62.5m
so
175mm on the map = 62.5m * 175 in real life = 10937.5mm
so X = 10937.5

MelodyOct 2, 2013

+118725

You are very welcome!

MelodyOct 2, 2013

+118725

4(x-4)+64=-2x

ok, get rid of the brackets first

4x-16 +64 = -2x

now add the like terms on the left (remember the minus sign belongs to the thing behind it, in this case 16) -16+64 = 64-16

4x + 48 = -2x

now you want the lots of x on one side and the numbers with no x on the other side If you take away 4x on the left side you will be left with just 48

4x-4x + 48 = -2x -4x
48= -6x
Now you need to get rid of -6 on the right side. The opposite of multiplying by -6 is dividing by -6. You have to do in to both sides.

48/(-6) = -6*x / -6
-8 = x

x = -8

You can check your answer LHS = 4(x-4)+64 = 4*(-8-4) +64 = 4 * -12 + 64 = -48 + 64 = 16
RHS = -2x = -2* -8 = 16
The left hand side equals the right hand side so the answer is correct.

MelodyOct 2, 2013

Melody:
25.28 is rational so long as it has not been rounded off. (If it was rounded off it may be an approximation for an irrational number)
cm^2 has nothing to do with it.

Any number that can be expressed exactly as a fraction can also be expressed exactly as a terminating or recurring decimal, and, all these numbers are rational.

Thank you!

GuestOct 2, 2013

+118725

Yes sure,why not.

MelodyOct 2, 2013

+118725

25.28 is rational so long as it has not been rounded off. (If it was rounded off it may be an approximation for an irrational number)
cm^2 has nothing to do with it.

Any number that can be expressed exactly as a fraction can also be expressed exactly as a terminating or recurring decimal, and, all these numbers are rational.

MelodyOct 2, 2013

+118725

Ok I got it, your a stands for arc and arcsin means inverse sin.

Solving it is easy
tan(asin(1/3) )
let alpha = arc sin (1/3)
so 1/3=sine alpha

Draw a right angled triangle
let alpha be one of the acute angles
sine alpha = 1/3 so put the 1 on the opposite side and 3 on the hypotenuse
Use pythagoras to get the other side
Now you can read the tan value straight off the triangle

Tan(arcsin(1/3)) = 1/(square root of 8) = (root2)/4

MelodyOct 2, 2013

+118725