81r^2-121d^2=

Solution for 81r^2-121d^2= equation:

Simplifying
81r2 + -121d2 = 0

Reorder the terms:
-121d2 + 81r2 = 0

Solving
-121d2 + 81r2 = 0

Solving for variable 'd'.

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

Add '-81r2' to each side of the equation.
-121d2 + 81r2 + -81r2 = 0 + -81r2

Combine like terms: 81r2 + -81r2 = 0
-121d2 + 0 = 0 + -81r2
-121d2 = 0 + -81r2
Remove the zero:
-121d2 = -81r2

Divide each side by '-121'.
d2 = 0.6694214876r2

Simplifying
d2 = 0.6694214876r2

Take the square root of each side:
d = {-0.818181818r, 0.818181818r}