When 18 is subtracted from four times a certain number, the result is 5/2 the original number.

What is the number?

4n - 18 = 2.5n

4n - 2.5n = 18

1.5n = 18

n = 18/1.5

n = 12

To find the number, we can set up an equation based on the given information.

Let's assume the certain number as "x."

The problem states that when 18 is subtracted from four times the certain number, the result is 5/2 the original number. Mathematically, we can express this as:

4x - 18 = (5/2)x

Now, to solve for x, we can begin by isolating the variable term by bringing all terms containing x to one side of the equation:

4x - (5/2)x = 18

To combine the x terms, we need to find a common denominator first, which, in this case, is 2. So, we have:

(8/2)x - (5/2)x = 18

Simplifying this expression, we get:

(3/2)x = 18

To isolate x, we can divide both sides of the equation by 3/2:

x = (18) / (3/2)

Dividing a fraction by another fraction is equivalent to multiplying by its reciprocal. Thus:

x = (18) * (2/3)

Simplifying further:

x = 36/3

x = 12

Therefore, the certain number is 12.