(-4 + 7i)(-4 - 7i)
= 16 - 49i2
Since i = √-1,
16 - 49i2
= 16 + 49
= 65
Answer: 65
Step-by-step explanation:
= -4(-4 - 7i) +7i(-4 - 7i)
= 16 + 28i -28i - 49i²
= 16 - 49(-1) Note: i² = -1
