dau puncte si coroana
plss

Răspuns:
a.)3x+7a+7b=
=15+91=
=106
b.)5(13)-50=
=65-50=
=15
c.)10x+4(13)=
=50+52=
=102
d.)(4 x 13-2x) x (2 x 13 - 5)=
=(52-10) x (26-5)=
=42 x 21=
=882