Explanation: To find the x, you need to start by adding your “like” terms on each side of the equal sign. This means the parts that you can add together. So, on the left side, you would add 3 and -9 together, which will make -6. Then, you would add x and 8x together, which would make 9x. So your left side will look like “9x-6”. There is nothing you can add together on the right side, so now you move on to the second step: combining the terms on both sides. You can do this by knowing that the opposite of subtraction is addition, and it’s the same the other way. Let’s look at our equation now: 9x-6=7x+4
9x and 7x are “like terms” so we can subtract. So now we have: 2x-6=4
We still need to make x be by itself, so now we can move the -6 over to the 4. We add because the opposite of subtraction is addition. So now we have: 2x=10
When a number is next to a missing number, that means they are being multiplied, and the opposite of multiplication is division. So we can divide 10 by 2, which equals five. So, x=5 and we can add that to our other missing number, CE. Replace “x” with “5” and you will see that CE=39.
