Q. Express as a complex number in simplest a+bi form:−5−6i10−5iAnswer:
Identify Conjugate: To simplify a complex fraction, we multiply the numerator and the denominator by the conjugate of the denominator. The conjugate of a complex number a+bi is a−bi. So, the conjugate of −5−6i is −5+6i.
Multiply by Conjugate: Now, we multiply both the numerator and the denominator by the conjugate of the denominator to eliminate the imaginary part in the denominator.(10−5i)×(−5+6i)/(−5−6i)×(−5+6i)
Distribute Multiplication: We distribute the multiplication in the numerator and the denominator.Numerator: 10×−5 + 10×6i + −5i×−5 + −5i×6iDenominator: −5×−5 + −5×6i + −6i×−5 + −6i×6i
Simplify Multiplication: We simplify the multiplication.Numerator: −50+60i+25i−30i2Denominator: 25−30i+30i−36i2Note that i2=−1.
Replace i2: We replace i2 with −1 and simplify further.Numerator: −50+60i+25i+30Denominator: 25+36Numerator: −20+85iDenominator: 61
Divide by Denominator: We divide the real and imaginary parts of the numerator by the denominator to get the complex number in a+bi form.Real part: −6120Imaginary part: 6185i
Final Answer: We write the final answer in a+bi form.Final answer: (−6120)+(6185)i