CPhill

The chances are 4/12 = 1/3

Twice as many = 30

y = 1/x²    

When x  →  0, y → ∞

As x moves away from the y axis in both directions, y → 0

So the range is (0, ∞ )

The side length is given by (1/64ft³)^(1/3) = (1/4)ft

OK..... f(3) means we put 3 into the function and evaluate this....so we have

2(3)^2 - 4(3) + 9  = 2*9 - 12 + 9  =  18 -12 + 9 = 15

And 2f(3) means we multiply this result by 2....so 2*15 = 30

And f(-3) means to do a likewise thing...so we have

2(-3)^2 - 4(-3) + 9 = 18 + 12 + 9 =   30 + 9 = 39

And 3f(-3) means to multiply this result by 3 = 39*3 = 117

So   2f(3) + 3f(-3)  =  30 + 117  =   147

And if we want one fraction, it equals  22 / 5..........

4137 / 32 =  129 + 9 / 32

We have

6x + 4 = 57         where x is the amount in each bag ...   subtract 4 from both sides...

6x = 53                divide both sides by 6

x = 53 / 6 = 8.83 kg in each bag