ElectricPavlov

The number EXACTLY in the middle between 25 and 31   is  (25+31)/2 = 28 

You really haven't given us enough info to answer your question unless we make some assumptions

Assumptions   #1  All tests are weighted equally

                       #2   "A" is 93 % 0r better

                       #3   No extra credit

(98 + 85 + final )/ 3  >= 93

Final must be at least: 96  

The FIRST equation says y = (x+1)     substitute this value into equation 2   

-2x - y = 7

-2x - (x+1) = 7

-2x -x -1 = 7

-3x = 8

x =- 8/3

Then since y= x+1

                     = -8/3 + 1

                     = -5/3      = y

There are various ways, depending on your decimal

example   .125  = fraction?     125/1000     then simplify  25/200   5 /40   1/8     the calc on this website will sometimes do this for you

example 2     .3333333333 ...     = fraction?

                 set x = .3333333....   then 10x = 3.33333.....     10x - x = 9x = 3.3333....   - .3333.....

                                                                                                          9x  = 3

                                                                                                            x = 3/9 = 1/3    

Do you have a SPECIFIC example???

As a FRACTION it is reduced as far as it will go   17/100        as a DECIMAL number = .17

use the following:

cos (47) = 200/hypotenuse

Hypotenuse = 200/(cos(47)) = 270.4 m

Use Pythagorean Theorem     (x+6)^2  = (x-21)^2  + x^2     Multiply this out and simplify to get

x^2 -54x +405 = 0

Then use quadratic formula to find  x = 45  

the sequence goes   subtract 7   subtract 6  subtract 5  subtract 4    subtract 3       77-3 = 74

74

The MINUMUM wt of all fo the boxes would be  20 + 20 + 20 + 20 + 25 =  105 lbs

The Maximum   would be                                  20 + 25 + 25 + 25 + 25 =  120 lbs

1/2 mile  /  3/10 hour  = 1/2 (10/3)  mile/hr   = 10/6 mph = 1 2/3 mph