12d - 9 = 15d + 9

Please check your problem again. It looks like you have an error.

OOps! My error.

12d - 9 = 15d + 9

12d - 15d = 9 + 9

-3d = 18
d = -6

how to solve -6r-5=7-12r

r+2

r=2

To solve the equation 12d - 9 = 15d + 9, we need to isolate the variable "d" on one side of the equation.

Let's go through the steps to solve it:

Step 1: Combine Like Terms
On the left side of the equation, we have 12d - 9. We cannot simplify it any further.
On the right side of the equation, we have 15d + 9. Again, we cannot simplify it any further.

Step 2: Move Variables to One Side and Constants to the Other
To isolate the variable "d," let's move the term with "d" to one side of the equation and the constant term to the other side. We'll achieve this by performing algebraic operations.

Add 9 to both sides of the equation:
12d - 9 + 9 = 15d + 9 + 9
This simplifies to:
12d = 15d + 18

Step 3: Combine Like Terms Again
We have 12d on the left side of the equation and 15d + 18 on the right side.

Step 4: Move Variables to One Side and Constants to the Other (Again)
This time, we'll move the "d" term to the same side as the 15d term, and the constant term to the other side.

Subtract 15d from both sides of the equation:
12d - 15d = 15d + 18 - 15d
This simplifies to:
-3d = 18

Step 5: Solve for the Variable
To solve for "d," we need to isolate it on one side of the equation. Since -3 is multiplying "d," we'll divide both sides of the equation by -3 to cancel it out.

Divide both sides of the equation by -3:
-3d ÷ -3 = 18 ÷ -3
This simplifies to:
d = -6

Therefore, the solution to the equation 12d - 9 = 15d + 9 is d = -6.