If a certain number is added to the numerator and denominator of 5/11, the result is 5/8. Find the number.

(5+x)/(11+x) = 5/8

so solve for x.

To solve this problem, let's break it down step by step:

Step 1: Understanding the problem
The problem states that if a certain number is added to both the numerator and denominator of the fraction 5/11, the result is 5/8.

Step 2: Set up the equation
Let's assign a variable, let's say "x", to represent the certain number that needs to be added to both the numerator and denominator.

The equation can be written as: (5 + x) / (11 + x) = 5/8

Step 3: Cross-multiply and simplify
To solve the equation, cross-multiply the fractions.

8 * (5 + x) = 5 * (11 + x)

Simplify both sides of the equation:

40 + 8x = 55 + 5x

Step 4: Isolate the variable
In order to solve for "x", we need to isolate the variable on one side of the equation.

Subtract 5x from both sides:

3x = 55 - 40

Combine like terms:

3x = 15

Step 5: Solve for the variable
To find the value of "x", divide both sides of the equation by 3:

x = 15/3

Simplify the division:

x = 5

Step 6: Answer the question
Therefore, the number that needs to be added to both the numerator and the denominator of 5/11 is 5.