Answer:
D. 57
Explanation:
For our first step, we are going to be converted the mixed number, 18 1/2, into an improper fraction. That makes it easier to work with!
18 1/2 = 37/2
^^^ Because, 18 * 2 is 36, plus the 1 from 1/2 = 37/2
1/3x - 1/2 = 37/2
Now, like a regular equation, we are going to add 1/2 to both sides:
1/3x = 38/2
Note - 38/2 is equal to 19, which is a whole number. Much much easier to work with!
1/3x = 19
And, finally, we multiply 3 on both sides. The reason is, we are doing opposite operations. This removes the 1/3.
x = 57
There!
Hope that helped!
-Mary