a) 2 la puterea x = 16
2 la puterea x =2⁴
x=4
b) 3 la puterea x = 243
3 la puterea x=3⁵
x=5
c) ( x + 1) ² = 144
( x + 1) ²=12²
x+1=12
x=12-1
x=11
d) 2 la puterea x + 2 la puterea x +2= 80
2 la puterea x(1+2²)=80
2 la puterea x*5=80
2 la puterea x=80:5
2 la puterea x=16
2 la puterea x=2⁴
x=4