All Answers

+130561

At the end of the first year, you get 100% of the 3300 plus 5% more.

In decimal terms, this equates to 1.00 + .05 = 1.05.

So, to find the amount of the raise after the first year, we just multiply 3300 * (1.05)

To find the amount after two years, we take what we had at the end of the first year (3300 * (1.05)) and multiply THAT by 1.05.

So we have........(3300 * 1.05) * (1.05 or 3300 * (1.05) ^2

Then, the "formula" to find the amount after N years is just........... 3300*(1.05)^N

I'll let you finish this one.....(remember to do the exponent part first and then multiply by 3300, unless you're putting the whole thing in a calculator to evaluate it all at once)

CPhillMar 27, 2014

+19

Thanks, I had a huge brain f**t which seems to be the only intelligence I can get out of my brain.

notsomathproMar 27, 2014

+130561

This isn't the most "mathematical" explanation.....but it might help anyway.

Let us suppose that something originally costs $100.

Now, let's suppose that we take 10% off. Well, looking at it another way, it must now just be "worth" 90% of what its original price was, i.e., $90.

Now, let's suppose that we take 15% off of that. Well, then the "new" price must just be 85% of the $90 (since we took 15% off), i.e., $76.50.

Well, the "final" price is just 76.5% of the original $100 price........thus we "took off" $23.50.....or 23.5% of 100 !!!

In terms of "math-speak," we could express this in the following way........100 - (100*.90*.85)......100 - (76.50)........Original Price - (Final Price) = "Discount"

This is simplistic, but I hope it helps you see it.......

CPhillMar 27, 2014

thank you very much!

GuestMar 27, 2014

+33666

unknown:
:? i need help.
A price is discounted by 15%. Then, the price is discounted by 10%. the combination of these is _______
I Know _______ = 23.5% but have no idea how to explain/ do the problem on my own. HELP!

Let the original price be P.
Then the first discounted price is (1-0.15)*P = 0.85P
The 2nd discounted price is then (1-0.1)*0.85P = 0.765P
The overall discount as a fraction is therefore (P-0.765P)/P = 0.235
Expressed as a percentage this is 23.5%

AlanMar 27, 2014

+33666

notsomathpro:
How would you solve a problem like 12=sqrt(16x)... because I won't always have access to this calculater and I can't seem to be able to figure out how the calculater did it?
Also is there a video I can watch that will show me how to do it?

Square both sides of the equation to get 12*12 = 16x (because squaring the square root of something just gives you that something). Now divide both sides by 16 to get x on its own.
12*12/16 = x, so x = 9

AlanMar 27, 2014

2403

itsjustmeMar 27, 2014

thank you so so much

GuestMar 27, 2014

+130561

We could use some fancy math here, but let's not.

Since a boy 6 feet tall casts a shadow 4 times his height (24 ft.), the flagpole must do the same.

Then the flagpole's shadow must be 4 times its height.

Then dividing 200 by 4, the height of the flagpole must be 50 ft.

And that it. No fuss, no muss.

CPhillMar 27, 2014

+130561

CPhillMar 27, 2014

+130561

X = 36 degrees

Call the apex point of the triangle A
Call the angle bisector AD, where D is the point where the bisector intersects the base of the triangle.

Let the vertexes counterclockwise from A be labeled B and C.

Then, in triangle ADC, AD = DC. And in any triangle having equal sides, the angles opposite those sides are equal, too. Therefore, < DCA (angle "X") = < DAC (one of the angles formed by the bisector).

And in triangle ABD, AB = AD, so the measure of angles ABD and ADB are equal.

And by the exterior angle theorem, angle ADB = DAC + DCA. Therefore, ABD = BAD + DCA.

And, because of bisection, angle BAD = DAC. And angle BAC equals their sum.

Therefore, ABD + BAC + DCA = 180.

Therefore, by substitution, BAD + DCA + BAD + DAC + DCA = 180 or, simplifying, 2BAD + 2DCA + DAC = 180.
But DCA = DAC., And DAC = BAD.
Therefore, DCA = DAC = BAC = BAD.

And substituting again......2DCA + 2DCA + DCA = 180

Therefore, 5DCA=180
Therefore DCA = 36 = X

Let's check that this is true. In triangle ABD....ABD = 72 angle ADB =72 and BAD = 36....these sum to 180
And, in triangle ADC, angle ADC is supplemental to angle ADB (i.e., 108) and DAC = 36 and DCA = 36...so these sum to 180, as well.

CPhillMar 27, 2014

+2354

Alan:
I'm sure I've answered this already! Have a look at: http://web2.0calc.com/questions/can-t-follow-reasoning

I'm truely sorry Alan, my wi-fi crashed when I uploaded it so I thought I'd lost it. Strangely enough I couldn't find it by using the search function either.

Thank you for your answer, I hadn't thought of dividing the two equation.

It is really helpful to me

reinout-gMar 27, 2014

solve(24^2+b^2=25^2, b)

GuestMar 27, 2014

+142

Melody:
Quote:
You have to forget the negative 7, you don't need it . You'll need it only if you are in a grafic...

The -7 can only be dismissed because Mthsmename has stated that it is a pythagorean question and a side length cannnot be negative.
If it was just a straight algebra question the -7 could not be dismissed. I know that you know this already Sam.

Interesting username you have there Mthsmename. You could sign up and make it official

Yep, that something I didn't think...

samgelinasMar 27, 2014

+33666

I'm sure I've answered this already! Have a look at: http://web2.0calc.com/questions/can-t-follow-reasoning

AlanMar 27, 2014

+893

reinout-g:
Bertie:
E5 must be 12.
It's not prime so it can't be at B5, it's divisible by 6 so can't go in C4 and it will be too big to go in A4 or D4.

Even though I'm currently at a point where I know you are right, at this point it still could've been at A3.

Be aware that in *15* they only mean the square which is diagonally at the right-bottom.