Hope this helps tried to color code it
X = 11/3 this answer is finding x in this problem
Exact form: 31/35
0.8857142~
The sum means addition.
Add the like terms together.
4x^3+2x^2-4x+3
+ 7x^3-4x^2+7x+8
4x^3 + 7x^3 = 11x^3
2x^2 + -4x^2 = -2x^2
-4x +7x = 3x
3 +8 = 11
The answer is : 11x^3 - 2x^2 + 3x + 11
B is correct the devotion is only 2 compared to 4.
A is wrong because variate A has higher trees then variate B
C is wrong because deviation for A is 4 compared to 2 ( opposite of B)
D is wrong because 4th one is 10 for A and 13 for B. 10 is not greater than 13