Answer:
x=7
Explanation:
First, add 15 to both sides (whatever you do to one side, do it to the other), this will help cancel out the -15 on the right side of the equation,
so 9x-15+15=7x-1+15, the 15 cancels out and we get 9x=7x+14
Now we want to simplify this further, lets subtract 7x from both sides,
9x-7x=7x-7x+14, 2x=14
Let's divide both sides by 2 because the 2 and x are held together by "multiplication" so we will break that bond with division and that will leave us with x.
2x/2=14/2
x=7
Our goal is to have a variable on one side and a number on the other, so that is why we are doing this. Also, notice that to solve this equation we were doing the reverse operation. For example, when we added 15 to both sides, we were performing the opposite of subtraction because we had a -15. Remember that variables are connected to numbers through multiplication, so 9x would be the same thing as 9*x
if you need a further explanation, feel free to ask in the comments!