Final answer:
To solve the equation 12 = 9r - 6x + 15, isolate the variable by manipulating the equation. Divide both sides of the equation by 9 to solve for r. The equation is equal to r - 6x - 3.
Step-by-step explanation:
To solve the equation, we need to isolate the variable. Start by adding 6x and 15 to both sides of the equation:
12 + 6x - 15 = 9r + 15 + 6x - 15
-3 + 6x = 9r
Next, divide both sides of the equation by 9 to solve for r:
(-3 + 6x) / 9 = (9r) / 9
-1/3 + 2/3x = r
Therefore, the equation 12 = 9r - 6x + 15 is equal to r - 6x - 3.