如图,等边的边长为3,为上一点,且,为上一点,若,则的长为 。
(+32)×(-60.6)×0×(-9)=______
-0.4×0.2=_______;
(-5)×(3)=_______;
(-3)×(-0.3)=_______;
确定下列各个积的符号,填在空格内: (1)(-7.4)×(-3.2)_______; (2)(-2)×(-2)×2×(-2)________; (3)(-)×(-)×(-)×(-)