Answer: The appropriate expression for the above problem is as follows:
2x + 15 = 9
Please note in your problem you are told the "sum of twice a number" which is 2 times any variable you select, and 15 which means to add. The word "is" means is "equal to."
2x + 15 = 9
-15 = -15
2x = -6
x = -3
We always want to check our work. Therefore, we substitute the -3 as the value for x in the above equation.
2(-3) + 15 = 9
-6 +15 = 9
9 = 9
Step-by-step explanation:
