a)(-5)×[3×(-5)-2×(-7)+9×(-3)]=
(-5)×(-15+14-27)=
(-5)×(-28)=140
b)[(-30)÷(+10)-(-8)×(+5)]÷(-37)=
[(-3)-(-40)]÷(-37)=
(-3+40)÷(-37)=
(-37)÷(-37)=1
c)(-50)×[1+42×(3-45)]×2+2=
(-50)×[1+42×(-42)]×2+2=
(-50)×(1-1764)×2+2=
(-50)×(-1765)×2+2=
88200×2+2=
176400+2=176402