ex 4 testul 1 aaaaaaaaa ms

x^2-(y-z)^2=42
x^2-(y^2-2yx+x^2)=42
x^2-y^2+2xy-x^2=42
42=-y^2+2yx=
=-1/42 y^2+1/21 yx=
=-1/42y^2+1/21yx
2x+2y-2z=12
2x+2y-24z=
2(x+y-12z)