Respuesta :

Answer:

x=4

Step-by-step explanation:

12x -7 = 8x + 9​

Subtract 8x from each side

12x-8x -7 = 8x-8x + 9​

4x -7 =9

Add 7 to each side

4x-7+7 = 9+7

4x = 16

Divide each side by 4

4x/4 = 16/4

x=4

Answer:

x=4

Step-by-step explanation:

To start solving 12x - 7 = 8x +9 I rearrange the equation so that we have the terms with x on one side of the equal sign and the terms without x on the other side.  Remember when we move a term across the equal sign we must switch the sign from negative to positive or positive to negative

I chose to put the terms with x on the left side of the equal sign by moving 8x, and changing its sign to negative

So on the left side we have 12x-8x

I moved the -7 to the right side of the equal sign to get

9 + 7

putting these together we have

12x -8x = 9 + 7

Now we can combine like terms, like terms are terms that have the same variable.  

Since 12x and 8x have the same variable "x" we can combine them by taking 8 away from 12 to get 4x

On the right side 9 and 7 both have no variable so we can combine theses as well, adding them we get 9+7= 16

So our equation now looks like

4x = 16

Next we want to get x on its own so we can find its value.

The x is being multiplied by 4 so to get the x on its own we would need to divide 4x by 4 to get x (4x/4 = 1)

However it is important to know that any operation done to one side of the equation must also be done to the other side, so we would need to divide the right side of the equation by 4

To visualise this: 4x/4 = 16/4

Since 4x/4=x and 16/4=4 our answer is x=4

Hope this helps :)