9f^2-1-20=0

Solution for 9f^2-1-20=0 equation:

Simplifying
9f2 + -1 + -20 = 0

Reorder the terms:
-1 + -20 + 9f2 = 0

Combine like terms: -1 + -20 = -21
-21 + 9f2 = 0

Solving
-21 + 9f2 = 0

Solving for variable 'f'.

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

Add '21' to each side of the equation.
-21 + 21 + 9f2 = 0 + 21

Combine like terms: -21 + 21 = 0
0 + 9f2 = 0 + 21
9f2 = 0 + 21

Combine like terms: 0 + 21 = 21
9f2 = 21

Divide each side by '9'.
f2 = 2.333333333

Simplifying
f2 = 2.333333333

Take the square root of each side:
f = {-1.527525232, 1.527525232}