Now we have the equation:Copy code3 - x = 12To solve it, we need to isolate x on one side. Let's go step by step:First, we want to get rid of the number 3 on the left-hand side. We’ll subtract 3 from both sides to focus on x:Copy code3 - x - 3 = 12 - 3This gives us:diffCopy code-x = 9Now, we have -x = 9. To get x by itself without the negative sign, we multiply both sides by -1 (which flips the signs):makefileCopy codex = -9So the solution is x = -9.If the variable has a negative sign, we just flip the signs at the end to get the value of x.