Which expression is equivalent to (4 + 6i)2?
-20 + 48i, 8 + 12i, 16 - 36i, 20 + 48i

Solution:

We know that, (a + b)2 = a2 + 2ab + b2

Given: (4 + 6i)2

Where, a = 4, b = 6i

Then,

= (4)2 + 2(4)(6i) + (6i)2

= 16 + 48i + 36i2

= 16 + 48i - 36  (i2 = -1)

= -20 + 48i

Therefore, the expression equivalent to (4 + 6i)2 is -20 + 48i.

Which expression is equivalent to (4 + 6i)2?

Summary:

The expression equivalent to (4 + 6i)2 is -20 + 48i.

Math worksheets and
visual curriculum