(9+2i)(9-2i)=

Solution for (9+2i)(9-2i)= equation:

Simplifying
(9 + 2i)(9 + -2i) = 0

Multiply (9 + 2i) * (9 + -2i)
(9(9 + -2i) + 2i * (9 + -2i)) = 0
((9 * 9 + -2i * 9) + 2i * (9 + -2i)) = 0
((81 + -18i) + 2i * (9 + -2i)) = 0
(81 + -18i + (9 * 2i + -2i * 2i)) = 0
(81 + -18i + (18i + -4i2)) = 0

Combine like terms: -18i + 18i = 0
(81 + 0 + -4i2) = 0
(81 + -4i2) = 0

Solving
81 + -4i2 = 0

Solving for variable 'i'.

Move all terms containing i to the left, all other terms to the right.

Add '-81' to each side of the equation.
81 + -81 + -4i2 = 0 + -81

Combine like terms: 81 + -81 = 0
0 + -4i2 = 0 + -81
-4i2 = 0 + -81

Combine like terms: 0 + -81 = -81
-4i2 = -81

Divide each side by '-4'.
i2 = 20.25

Simplifying
i2 = 20.25

Take the square root of each side:
i = {-4.5, 4.5}