2х+18     х-3 =12

I believe you mean to solve the equation:

2x + 18x - 3 = 12

To solve for x, we need to combine the like terms on the left side of the equation:

20x - 3 = 12

Next, we will isolate the variable x by adding 3 to both sides of the equation:

20x = 15

Finally, we will solve for x by dividing both sides of the equation by 20:

x = 15/20

Simplifying the fraction:

x = 3/4

Therefore, the solution to the equation is x = 3/4.