一个正方体纸盒的展开图如图,若将它折叠成正方体后,相对的面上的未知数是已知数的2倍,则(a+b)×c= .
: =0.25= ÷16= %==.
:32===6÷ = .
= :24=0.625=20÷ = .
比的前项是0.4,比值是,则比的后项是 .
=0.75= ÷12=1.8: = :24.