Rezolvati prin metoda reducerii sistemele:
4(x+2)+3(y+1)=15
5(x+1)+4y=11

2(x+1)-3(y-1)=-1
5(x-2)-4(y-3)=1

3(x+y)+2(y-x)=-5
4(x-y)-2(2x-y)=4

2(x+y)+3(y-x)=33
3(2x+y)+4(x-y)=-36