GRE
A's salary
C's salary
$$\sqrt{xy}$$
$$\frac{x+y}{2}$$
The greatest prime factor of 50
The greatest prime factor of 60
The length of the semicircle PQ
The sum of lengths of line segments PD, DC and CQ
$$x^{2}$$+$$\frac{1}{x^{2}}$$
$$x^{3}$$+$$\frac{1}{x^{3}}$$
$$k+\frac{1}{k^{2}}$$
$$k^{2}$$+$$\frac{1}{k^{3}}$$
$$m$$
$$n$$
25000 +道题目
252本备考书籍