Решите пример 99-30•(28+22): 50+124: 4=

99- 30 * (28+22):50  +124 :4 =
= 99 - 30 *50 :50  +31 =
= 99 -30 +31 = 100

по действиям:
1) 28+22 = 50
2) 30 *50 = 1500
3) 1500: 50 =30
4) 124:4 = (120:4) + (4:4) = 30+1 =31
5) 99-30 =69
6) 69+31 = (60+30)  + ( 9+1) = 90+10 =  100