1) (x-1)²=169, x-1 = +13 sau -13, Deci x1=14, x2=-12
2) (x+1)²=-16, x+1=+4i sau -4i, x1=-1+4i, x2=-1-4i
3) (x-2)²=-25, x-2=+/-5i, x1=2+5i, x2=2-5i
II. 1) z²=-16, z1=+4i, z2=-4i
2)z²=-50, z1=+√50*i=5√2*i, z2=-√50*i=-5√2i
3) z²=6i, z=a+bi, z²=a²-b²+2abi, Deci a²-b²=0, 2ab=6
a²=b², a=+/-b, a*b=3,
a=+√3, b=+√3, z1=√3+√3i
a=-√3,b=-√3, z2=-√3-√3i