If i^2 = - 1 and x = i + 9, which is the result of squaring x?

80 + 18i

Step-by-step explanation:

i² = - 1

x = i + 9

x² = (i + 9) ²

Applying; (a + b) ² = a² + 2ab + b² concept,

x² = i² + 18i + 81

We know that i² = - 1

So x² = - 1 + 18i + 81

x² = 81 - 1 + 18i = 80 + 18i