30*20-7*8 3000-7*40 40*50-138 70*30-9*50 (235+65)*3-645 (2600+1400):200-1350
30*20-7*8=544 3000-7*40=2720 40*50-138=1862 70*30-9*50(235+65)*3-645=403545 (2600+1400):200-1350=1330
1) 544 2) 2720 3) 1862 4) 1650 5) 255 6)-1330