2^(-1)=1/2
2^(-2)=1/4
cu acestea ecuatia este:
1/2 + x/4 - 1/4=0 aducem la numitor comun
2+x-1=0, x= - 1
b)
3(2x-9)/2 - 1/4=x/4+1/4:1/16
3(2x-9)/2 - 1/4=x/4+4 aducem la numitor comun
6(2x-9) - 1=x+16
12x - x= 16 +54 +1
11x=71
x=71/11
4^(-1):4^(-2)=1/4 : 1/16=1/4 x 16/1=4
ca regula generala: a^(-k)=1/a^k
