(1.5-1.2)*4*5=6立方分米6*(a+b)(5/6)*(2/3)=5/9吨(27+11)/2=19人(2/3)*(3/2)=1(3/8)/(4/7)=21/32(93-7*3)/6=12
6平方分米6(a+b)5/9吨2x-11=27x=192/3x=2/3x=14/7x=3/8x=21/327×3+6x=936x=72x=13