Răspuns:
Explicație pas cu pas:
3) x°y=xy-x-y+2
x°x=x²-x-x+2=10 x²-2x-8=0
x1,2=1±√1+8=1±3 x1=4 x2=-2
4)
x*y=x+y+2
x°y=xy+2x+2y+2
x²*y²=6 x²+y²+2=6 x²+y²-4=0 x ²+y²=4
x²°y²=14 x²y²+2x²+2y²=12 x²y²+2(x²+y²)=12 x²y²=12-8
aplicam Viete pentru un sistem care are ca solutii : x²si y²
t²-4t+4=0 ( t-2)²=0 x²=y²=√2
6
x*y=3xy-12x-12y-52
x°e=x 3xe-12x-12e-52=x
3xe-12e=13x +52 3e(x-4)=13(x+4) x≠-4
e=13/3
