a为有理数,且|a|=-a,则a是____.
若x=2是方程8-2x=ax的解,则a=_________.
单项式xy2的系数是_________.
-3的倒数是________.
.绝对值小于4的所有整数的和是_________.
请把0,-2.5,,- ,8,0.75这六个数按从小到大,依次填:________________.