Equation for "five elevenths times a number is 55"

Let the unknown number be x.

5/11 * x = 55

Since x is being multiplied by 5/11, and you want x alone, you need to multiply both sides of the equation by the reciprocal of 5/11 which 11/5.

11/5 * 5/11 * x = 55/1 * 11/5

x = 605/5

x = 121

Answer: The number is 121.