Solve for r 3r-9c=2r+18c

$3 r - 9 c = 2 r + 18 c$

Move all terms containing $r$ to the left side of the equation.

Subtract $2 r$ from both sides of the equation.

$3 r - 9 c - 2 r = 18 c$

Subtract $2 r$ from $3 r$ .

$- 9 c + r = 18 c$

Move all terms not containing $r$ to the right side of the equation.

Add $9 c$ to both sides of the equation.

$r = 18 c + 9 c$

Add $18 c$ and $9 c$ .

$r = 27 c$