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how do i write the expression in the standard form a+b i? (9-5 i)(3 + i )

How do I write the expression in the standard form a + b I.  ( 9-5 i) (3 + i)  ?

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Alex S. | Retired, Looking to Share My Love of Mathematics and ComputersRetired, Looking to Share My Love of Mat...
4.8 4.8 (75 lesson ratings) (75)
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(9-5i)(3+i) = 27 +9i -15i -5i^2 = 27 -6i -5*(-1) = 27+5-6i= 32-6i
 
Don L. | Don - Math/Science Tutor from Elementary School to College levelDon - Math/Science Tutor from Elementary...
4.9 4.9 (76 lesson ratings) (76)
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before i start, here are some notes for "i"
 
i = √(-1)
i^2 = -1
i^3 = -√(-1)
i^4 = 1
 
foil method for ( 9-5 i) (3 + i)
 
27+9i -15i -5i^2 = 27 - 6i - 5(-1) = 27 -6i +5 = 32 -6i
 
answer is 32 -6i