Question

Plz help me with this

Answer 1

(-4 + 7i)(-4 - 7i)

= 16 - 49i2

Since i = √-1,

16 - 49i2

= 16 + 49

= 65

Answer 2

Answer: 65

Explanation:

(-4 + 7i)(-4 - 7i)

= -4(-4 - 7i) +7i(-4 - 7i)

= 16 + 28i -28i - 49i²

= 16 - 49(-1) Note: i² = -1

= 16 + 49

= 65