ElectricPavlov

2x + 3y = 21 

is the same as    y = -2/3x + 7    slope , m = -2/3

Parallel slope is the same slope   -2/3

(-9- -17) / (2-j) = - 2/3     solve for 'j'

The question asks for squares that have included   12  BLACK  squares....    so  4x4  would not be included.

Thanx, Chris !    ~ EP

2cos^2x=cosx       Divide both sides of th equation by cos

2 cos x = 1

cos x = 1/2

x = pi/3    5 pi / 3

y /8   = 1 1/16

y/8  = 17/16      Now multiply both sides of the equation by 8

y = 136/ 16

y = 8 1/2

I think you will have to be given more information if you assume it is a conic section or other....

     but volume is basically a   3 dimensional  construct    l x w x h     or     area x h

            you increased the base area x4     and you increased the height by a factor of two

                        4 x 2 =   8 times the original volume        (without assuming a cylinder)

Expand to get

x^2 -3x -2 = 0         Use quadratic fromula        a = 1   b = -3   c = -2

\(x = {-(-3) \pm \sqrt{(-3^2)^2-4(1)(-2)} \over 2(1)}\)       to get your answer.............

Number =   294 105 ( 3)ⁿ             n = years

^{This is obviously exponential GROWTH as the number gets larger each year}

small bucket

   pi r^2 h = 850 cm^3

now make dimensions larger

   pi ( 2r)^2 2h  = ?

      (8)  pi r^2 h  = larger bucket

       (8) (850) = 6800 cm³

5 liters / 2 liters/recipe =   2.5 recipe

 recipe contains    100ml + 2 liters = 2.1 liters / recipe

2.5 recipe * 2.1 liters/recipe  = 5.25 liters