Q. Express as a complex number in simplest a+bi form:−9+2i24+23iAnswer:
Multiply Conjugate: Multiply the numerator and denominator by the conjugate of the denominator to remove the imaginary unit from the denominator.The conjugate of (−9+2i) is (−9−2i).−9+2i24+23i⋅−9−2i−9−2i
Apply Distributive Property: Apply the distributive property (foil method) to multiply out the numerators and the denominators.Numerator: (24+23i)×(−9−2i)=24×(−9)+24×(−2i)+23i×(−9)+23i×(−2i)Denominator: (−9+2i)×(−9−2i)=(−9)×(−9)+(−9)×(−2i)+2i×(−9)+2i×(−2i)
Perform Multiplication: Perform the multiplication for both the numerator and the denominator.Numerator: −216−48i−207i−46i2Since i2=−1, replace −46i2 with 46.Numerator: −216−48i−207i+46Denominator: 81−18i+18i−4i2Since i2=−1, replace −4i2 with 4.Denominator: 81+4
Combine Like Terms: Combine like terms in both the numerator and the denominator.Numerator: (−216+46)+(−48i−207i)=−170−255iDenominator: (81+4)=85
Divide Complex Numbers: Divide the numerator by the denominator to get the complex number in a+bi form.(−170−255i)/85=−170/85−(255i/85)
Simplify Fractions: Simplify the fractions.−85170=−2−85255i=−3iSo, the complex number in a+bi form is −2−3i.
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