To solve for a variable, you isolate that variable on one side and whatever that variable equals to is on the opposite side of that variable.
In the equation 7x - 1 = 9 we can see on the left-hand side that the x variable is being multiplied by 7 and -1 is being added to it.
Let's reverse whatever is being done to the x variable so that we can see its value.
Let's add 1 to the left-hand side of the equation. If we do that, then the -1 part will go away.
But remember, whatever we do on one side we must also do on the opposite side.
We do this to keep the equation balanced.
7x - 1 + 1 = 9 + 1
7x = 10
Now we have 7x = 10
We are very close seeing the answer. All we need to do is divide both sides by 7.
That way we will reverse the multiplication operation done to the x variable.
7x / 7 = 10 / 7
x = 10/7
So, A 10/7 is the answer.