help me............ex 9

Răspuns:
Explicație pas cu pas:
[(30+3)x10]-3+3=
=(33x10)-3+3=
=330-3+3=
=327+3=330
30+[3x(10-3)]+3=
=30+(3x7)+3=
=30+21+3=
=51+3=54
30+[(3x10)-(3+3)]=
=30+(30-6)=
=30+24=54
30+3x[10-(3+3)]=
30+3x(10-6)=
=30+3x4=
=30+12=42