Răspuns :
2.142+257=399
150-20=130
399-130=269
3.856-530=326
141+202=343
326+343=669
2.(142+257)-(150-20)= 399-130=269
3. (856-530) + (141+202)=326+343=669
2.142+257=399
150-20=130
399-130=269
3.856-530=326
141+202=343
326+343=669
2.(142+257)-(150-20)= 399-130=269
3. (856-530) + (141+202)=326+343=669