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• Complex Numbers
• Tests in Complex Numbers
• Multiplying complex numbers

# Multiplying complex numbers

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•  Question 1: 1 pts Is the following equation true or false? $$i^2 = -1$$
•  Question 2: 1 pts Is the following statement true or false? The product of two complex number can be real number.
•  Question 3: 1 pts Multiply: $-i\cdot(-i)$.
 $1$ $-1$ $i$ $-i$
•  Question 4: 1 pts Multiply: $(1-i)\cdot(1+i)$.
 $2$ $-2$ $2i$ $-2i$
•  Question 5: 2 pts Multiply: $(3+2i)\cdot(1+i)$.
 $1-5i$ $-1+5i$ $1+5i$ $-1-5i$
•  Question 6: 2 pts Multiply: $(5-3i)\cdot(-2-i)$.
 $8-i$ $7+i$ $12-i$ $-13+i$
•  Question 7: 2 pts Simplify: $(4-2i)^2$
 $12-16i$ $12+16i$ $20-16i$ $20+16i$
•  Question 8: 3 pts With what number do we need to multiply $1+i$ in order to get a real number?
 $i$ $-i$ $1-i$ $1+i$
•  Question 9: 3 pts With what number do we need to multiply $5-3i$ in order to get a real number?
 $5-3i$ $5+3i$ $3-5i$ $3+5i$
•  Question 10: 3 pts Simplify: $3i\cdot(1-i)^2$
 $6$ $-6$ $6i$ $-6i$