a)13+x=-3<=>x=-3-13<=>x=-16
b)x=13/5<=>x=2intreg si 3/5
c)2x
3.a)3,(3)=3 intreg si 3/9=30/9
b)0,3(6)=(36-3)/9=33/9=11/3
c)2,(12)=2 intreg si 12/99=2 intreg si 4/33=70/33
4...<=>x+2=0,5<=>x=0,5-2<=>x=-1,5
x/0,5=1<=>(scrie impartirea ca fractie si inmulteste pe diagonala)1*x=0,5<=>x=0.5
2x-1=0<=>2x=1<=>x=1/2<=>x=0,5
3(2x+1)=1<=>6x+3=1<=>6x=1-3<=>6x=-2<=>x=-2/6<=>x=-1/3
opusul= -13/5
inversul= 5?13
I-13.5I=13/5
6....=(aducem la numitorul comun-15) 10/15+12/15=22.15
0.5*2/3=1/3
...=1.2-1/6+6/9(num.comun-18)=9/18-3/18+12/18=18/18=1
2^(-2)*4=1/2^2*4=1/4*4=4/4=1