Va roggg urgentt!!!DOAR 4 SI 5!!!

Răspuns:
4. 428 5. a=1, b=169
Explicație pas cu pas:
4.{8+2•[9+9•(7+2•3)]}•2-4•23=
[8+2•(9+9•13)]•2-92=
(8+2•126)•2-92=
260•2-92=
520-92=
=420
5.a=5-4•[5-4•(5-4)]=
a=5-4•1
a=1
b=5+4•[5+4•(5+4)]=
b=5+4•(5+4•9)=
b=5+4•41
b=169
1•169=169=>13•13=169