三道方程题及答案，三道简算脱式计算

1.     2(x+8)=44/2      2.  3x+19=4成7   3.5(x-7)=12-7 

　         2x+16=22              3x+19=28         5x-35=5

　　          2x=22-16             3x   =9               5x =40

　　          2x=6                       x  =3                 x =8

　　          x  =3

1.13.75-(3.75+6.48)   2. 4.02＋5.4＋0.98
=4.02+0.98+5.4           =13.75-3.75-6.48
=10-6.48                     =5+5.4
=10.4                          =10.4

3.（0.75*42.7+57.3-0.573*25）/3*7972
=(0.75*42.7+57.3*1-57.3*0.25)/3*7972
=[0.75*42.7+57.3(1-0.25)]/3*7972
=[0.75*42.7+57.3*0.75]/3*7972
=[(42.7+57.3)*0.75]/3*7972
=75/3*7972
=25*7972
=199300