Q. 13i⋅(1−5i)=Your answer should be a complex number in the form a+bi where a and b are real numbers.
Write down multiplication: Write down the multiplication of the two complex numbers.We are given the complex numbers 13i and (1−5i), and we need to find their product.
Distribute first complex number: Distribute the first complex number over the second.To multiply these two complex numbers, we use the distributive property(a+bi)(c+di)=ac+adi+bci+bdi2.So, 13i∗(1−5i)=13i⋅1−13i⋅5i.
Perform the multiplication: Perform the multiplication.Now we multiply the terms:13i×1=13i (since anything times 1 is itself),and −13i×5i=−65i2 (since we multiply the coefficients and the imaginary units).
Remember i2=−1: Remember that i2=−1.The imaginary unit i has the property that i2=−1. We use this to simplify the term −65i2.−65i2=−65∗(−1)=65.
Combine real and imaginary parts: Combine the real and imaginary parts.Now we add the real part from step 4 and the imaginary part from step 3 to get the final answer.Real part: 65 (from −65i2),Imaginary part: 13i (from 13i⋅1).So, the product is 65+13i.
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