Question

2. Calculaţi:
10+(20+30)+30=1
(20+60)-(20+30)=1
300-70-10-20=
30+(200-40)+(3 000-600)=
80-(40+10)-50=
70+(200-30)+300=1
(100+70)-20+(30+20-40 =
500+(300-100)+(800-80)+100=​

Answer 1

2.


10 + (20 + 30) + 30 =

10 + 50 + 30 =

60 + 30 =

= 90



(20 + 60) - (20 + 30) =

80 - 50

= 30



300 - 70 - 10 - 20 =

230 - 10 - 20 =

220 - 20 =

= 200



30 + (200 - 40) + (3000 - 600) =

30 + 160 + 2400

190 + 2400

= 2590



80 - (40 + 10) - 50 =

80 - 50 - 50 =

30 - 50 =

= -20



70 + (200 - 30) + 300 =

70 + 170 + 300

240 + 300

= 540



(100 + 70) - 20 + (30 + 20 - 40) =

170 - 20 + (50 - 40)

170 - 20 + 10

150 + 10

= 160



500 + (300 - 100) + (800 - 80) + 100 =

500 + 200 + (800 - 80) + 100

500 + 200 + 720 + 100

700 + 720 + 100

1420 + 100

= 1520


Succes.