Question

Multiply and Simplify 3i(4-3i)-i(2+1)

Answer 1

Answer:

17+6i

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25

Step-by-step explanation:

2+3i

---------

4+3i

We want to multiply by the complex conjugate of the denominator

4+3i has a complex conjugate of 4-3i

2+3i             4-3i

--------- * --------------

4+3i           4-3i

Lets multiply the numerator

(2+3i) ( 4-3i)

2*4 +4*3i -3i*2 - 3i*3i =

8 +12i -6i - 9i^2

Remember i^2 = -1

8 +6i -9(-1)

17 +6i

Lets multiply the denominator

(4+3i) ( 4-3i)

4*4 +4*3i -3i*4 - 3i*3i =

16 +12i -12i - 9i^2

Remember i^2 = -1

16 -9(-1)

25

Putting numerator over denominator

17+6i

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25

Answer 2

9+9i is the answer b he hhjjfj