Answer:

Step-by-step explanation:
Let the number be x;
The product of 4 and the number will be;

The the square of the number is given as;

Taking the difference of both expressions above;

Factor out the common term:

Hence the difference between the product of 4 and a number and the square of the number is 
Answer:
361.7cm²
Step-by-step explanation:
Volume of sphere 1= 8cm³
=
Volume of sphere 2 = 647cm³
But volume of sphere = 4/3πr³
The radius of sphere 2
647 = 4/3πr³
((3*647)/4)/π= r³
5.36544 = r
Surface area = 4πr²
Surface area for the big sphere
= 4π5.36544²
= 361.7cm²
Step-by-step explanation:
1) if (0;0) if point A, (1;2) is point B; (-1;-2) is C, (2;1) is D, then
2) the vector AB is (1;2); vector AC is (-1;-2) and vector AD is (2;1), then
3) the length of AB, AC and AD are:



4) if the lengths above are equal, then it means that (0, 0) is equidistant from (1, 2), (-1, -2) and (2, 1).