The expression 30 / x is the same as 30 -x - x - x - x - x because division is repeated subtraction. Division divides a number into a specified number of group sizes. 30 / x where x = 6 means divide 30 into 6 groups. Within each group will be 5.
The expression 30 - x -x -x -x-x-x has 6 groups of x where each group is size 5.
