Thank you for the opportunity to help you with your question!

9 - x = 23 + x

Put like terms together. Take 9 to the right side of the equal sign and the x on the right side to the left side of the equal sign. when numbers cross the equal sign, they change the mathematical sign before them. therefore:

-x - x = 23 - 9

-2x = 12

diving both side by (-2) gives

x = 12/-2

Hence x = -6

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