What is x when 21 divided by x equals 87?

In other words, what would the divisor be if the dividend were 21 and the quotient 87?

To find the answer, just divide the dividend by the quotient: 21 ÷ 87 = 0.24137931034483

To prove this, let's compute 21 divided by 0.24137931034483: 21 0.24137931034483 = 87

How does it work?

Asking what the value of x could be when 21 divided by x gives a result of 87, is equivalent to solving the following equation:

21 x = 87

  1. Multiply both sides by x: 21 x x = 87 x
  2. 21 x x is equivalent to x x × 21 , which simplifies to 1 × 21 (or just 21 ).
  3. Thus, the equation becomes: 21 = 87 x
  4. To find x, divide both sides by 87: 21 87 = 87 x 87
  5. Which gives, after simplification: 0.24137931034483 = x (or x = 0.24137931034483 )

So, if the dividend is 21 and the quotient is 87, the divisor is 0.24137931034483.