Explicație pas cu pas:
17) {[(21-5)+12]:4+5}*10-[13*5-60]=
=[28:4+5]*10-(65-60)=
=12*10-5=
=120-5=
=115
18) 30+5*{4+5*[40+8*(40-36)]}=
=30+5*{4+5*[40+8*4]}=
=30+5*[4+5*72]=
=30+5*[4+360]=
=30+5*364=
=30+1820=1850
19) {[5:5+14]:3+3:[1+2*1]}:2=
=15:3+3:3:2=5+1:2=5+0,5=5,5
