17.85+25.17-1200
=17.(85+25)-1200
=17.110-1200
=1870-1200=670
745-5(120-74)-70
= 745-5.46-70
=745-230-70
=445
27.332+93.43+57.61+69.57
=8964+3999+57(61+69)
=12963+57.130
=12963+7410=20373
34.75+75.66-65.100
=75(34+66)-65.100
=75.100-65.100
=100(75-65)
=100.10= 1000.