You can find the weight of 1 load of stone by dividing 2/3 of a ton by 4, because there are 4 loads of stone in 2/3 of a ton, so (2/3)/4 = 2/12 = 1/6 of a ton, which is 1000kg/6 = 166,67kg, aproximately
The correct answer is: if is a root of , then is also a root of .
In fact, every polynomial has real and/or complex solutions. If all solutions are real, we're good. But if not all of them are real, then the complex ones come in couple of conjugate solutions. Since and are conjugate complex numbers, if one of them is a solution, the other must be as well.