geno3141

2°  is a plus 2

You want the temperature to be smaller, so use <

t < 2.

Let's see --- (1, 3)  means that  x = 1  and  y  = 3

5x - 9y  =  5(1) - 9(3)  =  5 - 27  =  -22

That's not 32!  So, (1, 3) is not a solution ...

log has base 10

ln has base e

This is a formula for the volume of a sphere.

If your problem looks like this:  3  <  2x + 6  < 18

Get the variable term alone in the center section by doing the same thing to all three parts.

First, get rid of the 6, by subtracting 6 from all three parts:

                  3 - 6  <  2x + 6 - 6  <  18 - 6

                        -3  <  2x  <  12

Now, divide all three parts by 2:

                     -3 ÷ 2  <  2x ÷ 2  <  12 ÷ 2

                        -1.5  <  x  <  6

For a rectangle:  Area  =  length x width   --->   A  =  l·w    or    l·w  =  A

--->   l·w  =  1/7

Now, to solve for l, divide both sides by w:

--->   l·w ÷ w  =  1/7 ÷ w

--->  l  =  1/7 ÷ w

Using the formula:  d  =  ½at² + v₀t

--->                    290  =  ½(-3.90)(12)² + v₀(12)

--->                   290  =  -280.8 + 12v₀  

--->                570.8  =  12v₀ 

--->                 47.6 m/s                        

To tell the difference between a relationship that is a function and one that isn't:

In a function, each x-value has only one y-value paired with it.

For instance,  y = x² is a function because any x-value that you choose has only one y-value paired with it:

           when  x = 2, y = 4         when x = -2, y = 4       when x = 0, y = 0      when x = 12, y = 144    etc.

    as points, these are:  (2, 4)                (-2, 4)                         (0, 0)                      (12, 144)    

           (using the same y-value twice is OK).

But  y²  =  x  is not a function because 

           when  x = 4, y can be either 2 or -2      

     as points, these are  (4,2)    (4, -2)            (using the same x-value twice isn't OK).

To find one-half of the sum, let's add them together and then divide by 2:

(n + 1) + (n + 2)  =  n + 1 + n + 2  

Dividing by 2,  (n + 1 + n + 2) / 2

What about fractions?        (.5)²  =  .25              (.5)³  =  .125

What about negatives?       (-2)²  =  4                (-2)³  =  -8              (-2)⁴  =  16

What about 0?                   (0)²  =  0                 (0)³  =  0

What about 1?                   (1)²  =  1                 (1)³  =  1

What about -1?                 (-1)²  =  1                (-1)³  =  -1              (-1)⁴  =  1

What do you think about Eliza's observation?