Răspuns:
Explicație pas cu pas:
280-21+0=259+0=259
349+36+10=385+10=395
520+100-72+9=620-72+9=548+9=557
7×5+9=35+9=44
(4÷4)+9+(28×6)-72=1+9+168-72=10+168-72=178-72=106
49+86+1+1=135+2=137
44+88-(48-21)+(145+7)=44+88-27+152=132-27+152=105+152=257
(84-64)÷5+(3×3+85)=20÷5+(9+85)=4+94=98