Define x:
Let the sum be x
Construct the equation:
The sum of 3 times a number and 5 is 2 times the number plus 15.
→ 3x + 5 = 2x + 15
Solve x:
3x + 5 = 2x + 15 | Equation
x + 5 = 15 | Take away 2x from both sides
x = 10 | Take away 5 from both sides
Answer: The number is 10.
