R^2-2.5-21=0

Solution for R^2-2.5-21=0 equation:

Simplifying
R2 + -2.5 + -21 = 0

Reorder the terms:
-2.5 + -21 + R2 = 0

Combine like terms: -2.5 + -21 = -23.5
-23.5 + R2 = 0

Solving
-23.5 + R2 = 0

Solving for variable 'R'.

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

Add '23.5' to each side of the equation.
-23.5 + 23.5 + R2 = 0 + 23.5

Combine like terms: -23.5 + 23.5 = 0.0
0.0 + R2 = 0 + 23.5
R2 = 0 + 23.5

Combine like terms: 0 + 23.5 = 23.5
R2 = 23.5

Simplifying
R2 = 23.5

Take the square root of each side:
R = {-4.847679857, 4.847679857}