做出如图图形的一条高.
21×42+21×63﹣21×5= .
(7.88+6.77+5.66)×(9.31+10.98+10)﹣(7.88+6.77+5.66+10)×(9.31+10.98)= .
10×+17×75%﹣7×0.75.
14﹣(12﹣18)= .
897×﹣37.5%+104×0.375= .