GRE
The area of the triangle RXT
The area of the trapezoid RSTU
$$a^2+b^2$$
$$\frac{1}{2} (a+b)^2$$
x
100
The number of different groups of 2 kittens that can be chosen from a litter of 8 kittens
The number of different groups of 6 puppies that can be chosen from a litter of 8 puppies
25000 +道题目
3本备考书籍