Question

3. Consider the complex numbers z and w below. Find the difference z-

w and the product z.w.
z = (1 – 3i) and w = (-2 + 5i)

Answer 1

see explanation

Explanation:

z - w

= 1 - 3i - (- 2 + 5i) ← distribute parenthesis by - 1

= 1 - 3i + 2 - 5i ← collect like terms

= 3 - 8i

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z × w

= (1 - 3i)(- 2 + 5i) ← expand using FOIL

= - 2 + 5i + 6i - 15i² [ i² = - 1 ]

= - 2 + 11i + 15

= 13 + 11i