Bonsoir,

a)

z+1/z-1 = 1 + i

(z+1) = (z-1)(1+i)

z+1 = z + zi - 1 - i

z - z - zi = -1 - i - 1

-zi = - 2 - i

z(-i) = - 2 - i

z = (-2-i)/(-i)

z = (-2-i)i/(-i)i

z = -2i + 1 / 1

z = 1 - 2i

S={1 -2i}

3) (3-2i)z/z+2 = i-5

(3-2i)z = (z+2)(i-5)

(3-2i)z = zi - 5z + 2i - 10

(3-2i)z - zi + 5z = 2i - 10

z(3-2i-i+5) = 2i - 10

z(8-3i) = 2i - 10

z = (2i-10)/(8-3i)

z = (-10+2i)(8+3i)/(8-3i)(8+3i)

z = -80 -30i + 16i - 6 / 64 + 9

z = -80 - 14i / 73

z = (-80/73) - (14/73)i

vous prenez z=x+iy

ensuite remplacez

sans oublier que i^2=-1

(x+iy)=(1+i)(x+iy-1)

(x+iy)=x+iy-1+ix-y-i

(x+iy)=(x-y)+i(y+x-1)-1

J ai oublie ca fait longtemps que j ai etudie ca donc j ai essaye de mon mieux donc c ce que je peux resoudre