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This is often confusing.....You just have to remember to "reverse" the inequality sign if you multiply or divide by a negative..

Example

3x >  6      divide both sides by 3

x  > 2   and this is true because if x = 4.....then  3(4) > 6  →  12 > 6

But, notice.....what if we had.....

-3x  > 6     divide both sides by -3 and reverse the sign

x <  -2       the reason for this is that if we kept the sign  as  ">"    we'd have an error

Note the error, here......

-3x >  6     divide by -3 and don't reverse the sign

x > -2        but if x > -2, then 0 should work in the original problem, right???

But  -3(0) > 6   =   0 > 6    and this clearly isn't true

So....by reversing the sign  we have x < -2   so..... something like -4 should work in the original problem

So.....

-3(-4) > 6    implies that 12 > 6 and that's true......!!!

So....just remember.....multiplying or dividing by a negative means that we have to reverse the signs  !!!

We have

(2 + x) / 2 = 6        and   (1 + y) / 2  = 4

2 + x   = 12                      1  +  y  = 8

x = 10                                  y = 7

So...the other endpoint is    (10. 7)

We need more clarification, here...

What is   18 7 6  km  ???? 

Yes Chris, I understand that but they must be used to measure something.

Here is an article

V = (4/3) * pi * (50 * 2/3)^3  =

155140.3779 =

about  1.55 x 10^5   cm^3

@@ End of Day Wrap   Mon 6/4/15    Sydney, Australia    Time 12:45pm  (Really Tues morn)  ♪ ♫

Good evening all,   

Our wonderful answerers today were CPhill, Nauseated, Alan, MathGod1.  Thank you   

Interest posts:

Tues 7/4/15

FTJ means "For the Juniors"

No...they are just linear parts of a meter.........

Thanks Chris - do picometres measure atoms or molecules or what?

Thanks Chris and Alan. :)

It did look a lot harder than it really was :)

+-1--1 how can i do this one please ?

Think of negative numbers as cold numbers and positive numbers as hot numbers (just like with temperature)

if you add cold into a room then the room will get colder   SO  +- = -

if you take cold out of a room then the room will have to get warmer.    SO   - - = +

SO

+-1--1 =  -1 +1 = +1 - 1 = 0

Melody....I think "nm" and "pm" refer to nanometers and picometers......I could be wrong, however...!!!

What does pm stand for?  What are they used for?

100%-37.5% = 62.5%

62.5/100*216=

1) I borrow a mortgage of £185,000 over 30 years at an interest rate of 4.1%. How much will I pay back overall?

This is a present value of an ordinary anuity problem

i=0.041,  PV=185000, n=30,   C is your yearly repayment (you will pay back 30C)

y-1/3>2/3

y>2/3   +   1/3

y>   1

--- little small 2

what does that mean?

28° 50 .....convert this to decimal form.....  

28.833°  x  pi / 180   = about 0.5032 rads

Hi GoledenLeaf, great work Chris 

I love the way formulas can make graphs that have such weird shapes.

3D graphs get even better.   

 Thanks

! : Is emphasis to something loud

! : Is used in Permutation

I knew that you got it from the web.  It is a good pic.  Pictures make answers so much easier to understand.

They also make answers look 'prettier' and 'pretty' answers are less intimidating to work through. :)

What do you mean?

Multiply .08 by whatever your buying and add solution to the item to find the total.