GRE
y
1
(1.98)(81)(99)(1,249)
25,000,000
$$\frac{(k+1)!}{(k-1)!}$$
(k)(k+1)
The average (arithmetic mean) of x and y
The average (arithmetic mean of 2x and $$\frac{y}{2}$$
$$5(2^{x})$$
$$4(3^{x})$$
The perimeter of quadrilateral ABCD
8r
The circumference of either circle
The length of line segment RT
25000 +道题目
245本备考书籍