Q. Express as a complex number in simplest a+bi form:−10+10i30−10iAnswer:
Write Given Complex Fraction: Write down the given complex fraction.We are given the complex fraction (30−10i)/(−10+10i) and we need to express it in the form a+bi.
Multiply by Conjugate: Multiply the numerator and the denominator by the conjugate of the denominator.The conjugate of the denominator −10+10i is −10−10i. We multiply both the numerator and the denominator by this conjugate to remove the imaginary part from the denominator.(−10+10i)(−10−10i)(30−10i)(−10−10i)
Multiply Numerator: Perform the multiplication in the numerator.(30−10i)(−10−10i)=30(−10)+30(−10i)−10i(−10)−10i(−10i)=−300−300i+100i+100=−200−200i+100i2Since i2=−1, we have:=−200−200i−100=−300−200i
Multiply Denominator: Perform the multiplication in the denominator.(−10+10i)(−10−10i)=(−10)(−10)−10i(−10)+10i(−10)−(10i)(10i)=100+100i−100i−100i2Since i2=−1, we have:=100+100i−100i+100=200
Divide by Denominator: Divide the numerator by the denominator.We have the numerator as −300−200i and the denominator as 200. Dividing the numerator by the denominator gives us:(−300−200i)/200=−300/200−(200i/200)=−1.5−i