По действиям 70*6+80-540: 5; 340+60-320: 8*4; 340*2-480: 4

70*6+80-540:5 = 312
1)70*6 = 420
2) 540:5 = 108
3) 420-108 = 312

340+60-320:8*4 = 390
1) 8*4 = 32
2) 320: 32 = 10
3) 340+60 = 400
4) 400 - 10 = 390

340*2-480:4 = 560
1) 340*2 = 680
2) 480:4 = 120
3) 680 - 120 = 560