12+3i=213−313i Explanation: 12+3i is reciprocal of complex number 2+3i. To find reciprocal we multiply numerator and denominator each by complex conjugate of 2+3i, which is 2−3i. Hence, 12+3i=12+3i×2−3i2−3i =2−3i22−(3i)2 =2−3i4−9i2 =2−3i4+9 =213−313i