19.89=-0.9r

Solution for 19.89=-0.9r equation:

Simplifying
19.89 = -0.9r

Solving
19.89 = -0.9r

Solving for variable 'r'.

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

Add '0.9r' to each side of the equation.
19.89 + 0.9r = -0.9r + 0.9r

Combine like terms: -0.9r + 0.9r = 0.0
19.89 + 0.9r = 0.0

Add '-19.89' to each side of the equation.
19.89 + -19.89 + 0.9r = 0.0 + -19.89

Combine like terms: 19.89 + -19.89 = 0.00
0.00 + 0.9r = 0.0 + -19.89
0.9r = 0.0 + -19.89

Combine like terms: 0.0 + -19.89 = -19.89
0.9r = -19.89

Divide each side by '0.9'.
r = -22.1

Simplifying
r = -22.1