Answer:
6 + x = 9
Step-by-step explanation:
We know that x = 3, and that we need to add x (which equals 3) to 6.
So, all we need to do is add 6 + 3.
6 + x = 9
We know this because for the expression 6 + x, we replace x with it's given value, which is 3.
⬇
6 + 3 = 9
