Answer:
Step-by-step explanation:
Note all operations:
- twenty-five <em>more than → </em>addition → +25
- <em>twice</em> <u>a numbe</u>r → multiplication → ×2
- <em>is</em> fifty-five → equal to → =55
Create an equation, and make the unknown number be x. 25 is added to x multiplied by 2, which, in all, equals 55:

Now solve for x. Subtract 25 from both sides:

Divide both sides by 2:

The number is equal to 15.
:Done
CHECK:
Insert the value of x to see if it is true:

This is true, so the value of x is also true.