Răspuns:
19+(42-18)-18= 19+24-18= 19+6=25
73-58+25=73-83= - 10
3x12:6= 3 x2= 6
30+ 4+ 56-10=34+46=70
20-(15-5) : (26-18)= 20-10:8=10:8=1,25
40: 15+0:56=40:15+0=2.6
89+8x7-4=89+56-4=89+52=37