30分之一(-三分之二+五分之三)/(-2)
=[1/30×(-2/3)+1/30×3/5]/(-2)
=[1/50-1/45]/(-2)
=(1/450)/2
=1/900
(0.1)平方*(-五分之二)方
=1/100*4/25
=1/625
3b方-(a方+b方)-b方
=3b²-a²-b²-b²
=b²-a²
30分之一(-三分之二+五分之三)/(-2)
=[1/30×(-2/3)+1/30×3/5]/(-2)
=[1/50-1/45]/(-2)
=(1/450)/2
=1/900
(0.1)平方*(-五分之二)方
=1/100*4/25
=1/625
3b方-(a方+b方)-b方
=3b²-a²-b²-b²
=b²-a²