The given expression is:

There are 3 terms in this expressions:
1)

2)

3) 2
The coefficient of

is 3.
The coefficient of

is -7.
The constant term is 2.
A) this is not enough information to compare the mode.
For example:
{1,1,6,11,11]: mean 6, median 6, mode 1 and 11
{4,4,6,8,8} mean 6, median 6 mode, mode 4 and 8
To work out the mean of a data set add all the numbers together and divide them by the number of data items there are.
18 + 14 + 8 + 22 + 25 + 8 = 95
95/6 = 15.8 (that answer is rounded)
Because there is no number that could be multiplied BY ITSELF and still be negative:
-2 x -2 = 4
2 x 2 = 4
But, cubed root works because a negative can be three times and still be negative:
-4 x -4 x -4 = -64
Hope this helps!