I have to perform the indicated operation by writing the result in the form a + bi?

Question

I have the problem (9-54i)(6-i) with multiply choice answers. The answer I came up with does not match any of the multiply choice answer. The answer I am getting is 54-63i+54i^2 which converts to 54+54(-1)-63i with the answer of -63i. The multiply choice answers are (A) 108+333i (B) 9i (C) 108-333i or (D)-333i. Am I figuring wrong, please someone help!!

Answer 1

D -333i

Answer 2

The answer is D and that is because when you FOIL the question you get "54-9i-324i+54i^2" which goes to "54-333i+54i^2) and the 54 cancels which leave -333i

Answer 3

D)
54 - 9i - (54*6)i + 54(i^2)
54 - 333i - 54
333i

Answer 4

(9-54i)(6-i)

Following the FOIL method you should have gotten
54 -9i - 324i +54i^2

54 -333i +54(-1)

= -333i
which is answer Option D.

Guess you just missed out on the -324i ??

Answer 5

The answer is -333i

(9-54i)(6-i)=54-9i-324i+54i^2
=-9i-324i
=-333i

Answer 6

(9 - 54i)(6 - i)
54 - 9i - 324i + 54i^2
54 - 333i + 54(-1)
54 - 333i - 54
-333i

ANS : D.) -333i

i^2 = (sqrt(-1))^2
the sqrt and ^2 cancel out
i^2 = -1

Answer 7

Your 54 and -54i^2 parts are correct, but you didn't multiply the 6*-54i and the 9*-i parts. first (9*6), inner (-54i * 6), outer (9*-i), last (-54i * -i). Multiply all those and add them together. Got it?

Answer 8

remember FOIL (multiply first terms, then outiside, then inside, then last)

54 -304i-9i+54i^2

-333i

Answer 9

(a + bi) (c + di) = (ac - bd) + (ad + bc)i

(9 - 54i) (6 - i) = (54 - 54) + (-9 - 324)i

= 0 + (-333)i

= 0 - 333i

Answer 10

9 * 6 = 54
-54i * -i = -54
9 * - i = -9i
6 * -54i = -324i
= - 333i

Answer 11

complicated volume aspects calculate the picture of ordinary numbers, you in ordinary words ought to recollect that i² = -a million. (24 - 4i)(6 + i) = 24 * 6 - 4i * 6 + 24 * i - 4i * i = one hundred forty four - 24i + 24i - 4i² = one hundred forty four - 4i² = one hundred forty four - 4(-a million) = one hundred forty four + 4 = 148