(3r+5f)(3r-5f)=

Solution for (3r+5f)(3r-5f)= equation:

Simplifying
(3r + 5f)(3r + -5f) = 0

Reorder the terms:
(5f + 3r)(3r + -5f) = 0

Reorder the terms:
(5f + 3r)(-5f + 3r) = 0

Multiply (5f + 3r) * (-5f + 3r)
(5f * (-5f + 3r) + 3r * (-5f + 3r)) = 0
((-5f * 5f + 3r * 5f) + 3r * (-5f + 3r)) = 0

Reorder the terms:
((15fr + -25f2) + 3r * (-5f + 3r)) = 0
((15fr + -25f2) + 3r * (-5f + 3r)) = 0
(15fr + -25f2 + (-5f * 3r + 3r * 3r)) = 0
(15fr + -25f2 + (-15fr + 9r2)) = 0

Reorder the terms:
(15fr + -15fr + -25f2 + 9r2) = 0

Combine like terms: 15fr + -15fr = 0
(0 + -25f2 + 9r2) = 0
(-25f2 + 9r2) = 0

Solving
-25f2 + 9r2 = 0

Solving for variable 'f'.

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

Add '-9r2' to each side of the equation.
-25f2 + 9r2 + -9r2 = 0 + -9r2

Combine like terms: 9r2 + -9r2 = 0
-25f2 + 0 = 0 + -9r2
-25f2 = 0 + -9r2
Remove the zero:
-25f2 = -9r2

Divide each side by '-25'.
f2 = 0.36r2

Simplifying
f2 = 0.36r2

Take the square root of each side:
f = {-0.6r, 0.6r}