Perform each operation. Write answers in standard form. -5i(3-i)²

Question

Accepted Answer

Hello everyone. We're going to perform multiplication on the expression negative seven I times nine minus I squared. We're going to make sure our answer is in standard form. So I recall that when I had a binomial squared I could make that into a perfect square Trina meal. So that's what I'm gonna do. So I'm rewriting negative seven I and I will take care of that part after and then a binomial squared I can square the first term and get 81. So nine squared is 81 square the last term. So I squared as I squared take the product of the two terms. So multiply nine times negative I get negative nine I and then double it. So negative 18. I so I've done the first part of multiplication and right now I have negative seven I times 81 minus 18. I plus I squared before I do anything further I recall that I squared is the same as negative one. So I'm gonna plug that in and then simplify inside my parentheses. So I have negative seven I on the outside the parentheses inside I have 81 minus 18. I and I said I squared is the same as negative one. So I now have plus a negative one cleaning up what's on the inside of those parentheses Again negative seven I squared is still on the outside my like terms on the inside is the the negative one Which will combine into a positive minus 18. I So now I'm going to distribute this in. So right now I have negative seven I times -18 I. So using the distributive property negative seven I times 80 will give me negative 560 I and then negative seven I. Times negative 18. I will give me a positive 126 I squared. So again recalling that I squared is negative one. I'm gonna substitute that in. I have negative 560 I plus 126 times negative one 126 times negative one gives me negative and I'm gonna leave my real part first. So negative 126 minus I. So now it should be in standard form yep it is the real part is first and that is our solution negative minus 560 I. Which is answer choice B. Have a nice day.

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Perform each operation. Write answers in standard form. -5i(3-i)²

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