At the schoolhouse in Mathematician City, Aunt Sally is quietly reading her Math book. Add and Minus are busy doing their assignment while Multiply and Divide are doing something fun. The two are imaginary friends. Multiply has something to say about what does "i" means. "Hey, Divide? I have a question to ask you. What is "i" means to you?" "Well, let's set this an example shall we?" He replied. "I have 5i(5i) equals to twenty-five i square. That's the same thing as using the value x. Now, that twenty-five square needs to be removed. i square equals to negative one. So, twenty-five i square changes to negative twenty-five. Another thing, if you have negative twenty-five square, it would change that to positive twenty-five as a regular number." "Why does twenty-five i square go away. I thought it stay as a correct answer like the rest of the equation does?" "Well, rules are rules, Multiply. i equals one, i square equals negative one, i cube equals square root of negative one. You can also F.O.I.L. them like this (6-5i)(4-9i). That stands for first, outer, inner, and last. That equals to 24-54i+20i+45i square. Uh oh, we need to get rid of forty-five i square. That changes to negative forty-five as a basic number. Negative forty-five and twenty-four combines to negative twenty-one. So does negative fifty-four i and twenty i equals to negative thirty-four i. The correct answer is -21-34i. That's why you're my imaginary friend, Multiply."

 

 

 

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