Final answer:
The solutions to the equation 5c^(4)-405=0 are x = 9 and x = -9.
Step-by-step explanation:
The equation 5c^(4)-405=0 is a quadratic equation in the form ax^2 + bx + c = 0, where a = 5, b = 0, and c = -405. To solve this equation, we can use the quadratic formula:
x = (-b ± sqrt(b^2 - 4ac)) / (2a)
Substituting the values into the formula, we get:
x = (0 ± sqrt(0 - 4(5)(-405))) / (2(5))
x = ± sqrt(8100) / 10
x = ± 90 / 10
x = ± 9
Therefore, the solutions to the equation are x = 9 and x = -9.