Answer:
Explanation:
First of all, what does this problem mean? What is x?
x is an unknown variable. What does x + 3 = 9 mean? If you add something to x, you get 9. To find x, we need to isolate x in the equation.
What does it mean to isolate x?
In an equation, there are two sides which are equal to each other in value. Whatever we do to one side, we do the same to the other. If we minus (a) value(s) on each side, we can finally isolate x. Once we have isolated x, we can simplify the other side of the equation if we need to. Let's try, then! It's an easy one.
x + 3 = 9
What will we do to isolate x?
To isolate x, we can minus three on each side. This will then cancel out the + 3 in (x + 3) and we can isolate x. But we also have to minus three on the other side, too! 9 - 3 = 6.
x + 3 = 9
- 3 - 3
We are subtracting 3 on each side, cancelling out the + 3 on the (x + 3) side of the equation. This will then isolate x, and we can find out what x is!
x + 3 - 3 = 9 - 3
x = 6
You did it! You can solve simple pre-algebra equations! Make sure to practice and comment down below if you have any questions! :)