ElectricPavlov

If you are looking at the TOTAL rolls as an outcome, there are  6 x 6 x 6 x 6 x 6 x 6   possible outcomes    6^6 = 46656 possibilities

Use pythag theorem

9^2 + h^2 = 15^2

h= 12ft

(1/2)^20/10  =( 1/2)^2  = 1/4

You can use the Quadratic Formula as previously illustrated.    You can also 'complete the square'

Take 1/2 of the 'x' coefficient, square itn and add it to both sides:

x^2 -4x + (-2^2) = 11 + (-2^2)

x^2 -4x +4 = 15

(x-2)^2 = 15         Now take the sqrt of both sides

x-2 = +- sqrt15

x = 2 + or - sqrt15        (same answers as Quadratic Formula)

1.08 kg   is 1080 gm = 1,080,000 mg

each plant gets 97mg x 3  each year = 291mg

1080000/291 = 3711.34   or   3711 plants    He will have enough fertilizer left over for .34 plants      .34 x (291) =  98.94 mg left over

OK....we'll answer BOTH of your posted questions

Equation of a line  :  y = mx + b    m = slope   b= y axis intercept

slope is rise/ run    ....for the two popints you have listed =  (4-(-8))/ (6-(-3))  =   12/9

y= 12/9 x + b     substitute one of your points

4= 12/9 (6) + b

4 = 72/9 + b

4 = 8 + b          b= -4

y= 12/9x -4    is the equation for your line    the y intercept is where x= 0       -4

the x-intercept is where y= 0       0 = 12/9x -4      x= 4 (9/12) = 3     

Sept   30 day   + Oct 31 days + nov 30 days + dec 31 days + January 10 days = 132 days

ok      Type   '3'      then the sqrt sign ( the key TWO to the left of '1')      then '='       Ta Da!

....or gradian mode......    some calculators have  'DRG'   key to switch between.....their should (may) be an indicator on the display to alert you to which mode you are currently using.....