a) 12+13×4=12+52=64
64=8 la puterea a doua
b)2 la a patra +3 la a doua = 16+9=25
25=5 la puterea a doua
c) 249-336:2=249-168=81
81=9 la puterea a doua
d)2 la a doua + 3 la a 3 a +5=4+27+5=36
36=6 la puterea a doua
e)2 la a treia ×9+3 la a 4 a= 8×9+81=72+81=153
153 nu e pătrat perfect
f)10 la a 2 a - 8 la a 2 a =100-64=36
36 = 6 la puterea a doua