求(lg2)2+lg2·lg50+lg25的值.
若函数y=(x≤-1),则f-1(2)= .
若数列{an}满足an+1=且a1=0,则a7= .
若f(10x)=x,则f(5)= .
(x,y)在映射f下的象是(xy,x+y),则点(2,3)在f下的象是 .
若2x-3-x≥2-y-3y,则
A.x-y≥0 B.x-y≤0 C.x+y≥0 D.x+y≤0