Răspuns:
.
Explicație pas cu pas:
1. [(1+4):5+9]x78
(4:5+9)x78
(1+9)x78
10x78=780
2.[(10+20)+25]:5
(30+25):5
55:5=5
3.900+300:10-(76-84)
3900+300:10-8
3900+30-8
3930-8=3922
4.[(1+4):5+9]x1000+700:100+11x8
(4:5+9)x1000+700:100+11x8
10x1000+700:100+11x8
10000+700:100+11x8
10000+7+11x8
10000+7+88
10007+88
10095
5.[420:(160-125)+25x4]x100
(420:35+25x4)x100
(12+25x4)x100
(12+100)x100
112x100
11200
6.[20x(8-4)+2x10]:10+17x100
(20x4+2x10):10+17x100
(80+2x10):10+17x100
(80+20):10+17x100
100:10+17x100
10+17x100
10+1700
1710
