1 the sum of two numbers, x and y, equals twice their products. if x=3, what is the value of y?
这道题没大看懂?请问大家是这样么?x+y=2(x+y)
x+y=2xy,求y.
2 if x is an integer and x2(x的平方)<37,what is the greatest possible value of x minus the least possible value of x?
我觉得这道题x的最大值为6,最小值为0,所以选6.
a.5 b.6 c.10 d.12 e.36
选D，最大为6，最小为-6.
3 三角形ABC，角B=X度，X>90 度，比较三角形的周长与3倍AC的长度的大小，答案是B
AC是最大边,所以AB+BC+AC
2.0
比较the greatest value of p(1-p)与1/2的大小，答案是C
答案错了,选B p+(1-p)>=2p(1-p)^1/2 => p(1-p)<=1/4 < 1/2
