81-49u^2=0

Solution for 81-49u^2=0 equation:

Simplifying
81 + -49u2 = 0

Solving
81 + -49u2 = 0

Solving for variable 'u'.

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

Add '-81' to each side of the equation.
81 + -81 + -49u2 = 0 + -81

Combine like terms: 81 + -81 = 0
0 + -49u2 = 0 + -81
-49u2 = 0 + -81

Combine like terms: 0 + -81 = -81
-49u2 = -81

Divide each side by '-49'.
u2 = 1.653061224

Simplifying
u2 = 1.653061224

Take the square root of each side:
u = {-1.285714286, 1.285714286}