Given, √x2−2x+8+(x+4)i=y(2+i) On equating real and imaginary parts, √x2−2x+8=2y ⇒‌‌x2−2x+8=4y2‌‌... (i) and x+4=y ⇒‌‌x=y−4‌‌ [put in Eq. (i)] ∴‌‌(y−4)2−2(y−4)+8=4y2 ⇒‌‌3y2+10y−32=0 ⇒‌‌(y−2)(3y+16)=0 ⇒‌‌y=2,‌