(9x*9x)-16=0

Solution for (9x*9x)-16=0 equation:

Simplifying
(9x * 9x) + -16 = 0

Reorder the terms for easier multiplication:
(9 * 9x * x) + -16 = 0

Multiply 9 * 9
(81x * x) + -16 = 0

Multiply x * x
(81x2) + -16 = 0

Reorder the terms:
-16 + (81x2) = 0

Solving
-16 + (81x2) = 0

Solving for variable 'x'.

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

Add '16' to each side of the equation.
-16 + 16 + (81x2) = 0 + 16

Combine like terms: -16 + 16 = 0
0 + (81x2) = 0 + 16
(81x2) = 0 + 16

Combine like terms: 0 + 16 = 16
(81x2) = 16

Divide each side by '81'.
x2 = 0.1975308642

Simplifying
x2 = 0.1975308642

Take the square root of each side:
x = {-0.444444444, 0.444444444}