新
If 1+x+x^2+x^3=60, then the average (arithmetic mean) of x, x^2, x^3, and
x^4 is equal to which of the following?
A 12x
B 15x
C 20x
D 30x
E 60x
这个题直接在等式的两边乘以x就好了，然后除以4，答案就是B
新
If 1+x+x^2+x^3=60, then the average (arithmetic mean) of x, x^2, x^3, and
x^4 is equal to which of the following?
A 12x
B 15x
C 20x
D 30x
E 60x
这个题直接在等式的两边乘以x就好了，然后除以4，答案就是B