Final answer:
To find the number, set up an equation and isolate the variable x. After performing the necessary operations, x is equal to 65.
Step-by-step explanation:
Let's call the number x. According to the problem, if 91 is added to x, the result is 39 less than three times x. We can write this as: x + 91 = 3x - 39. To solve for x, we need to isolate it on one side of the equation. Subtracting x from both sides gives us 91 = 2x - 39. Adding 39 to both sides, we get 130 = 2x. Finally, dividing both sides by 2, we find that x = 65.
Learn more about Solving equations involving unknown numbers