Final answer:
A two-digit number with units digit x and tens digit y is represented as 10y + x. This is because the tens digit value is multiplied by 10 and the units digit retains its individual value.
Step-by-step explanation:
In mathematics, when we represent a two-digit number with the units digit being x and the tens digit being y, the correct representation of the number in a mathematical form is 10y + x. Each digit in a number has a place value, and in the case of a two-digit number, the tens digit represents the number of tens while the units digit represents the single units.
For example, if we have a number with a units digit of 6 (x=6) and a tens digit of 3 (y=3), the number would be represented as 10*3 + 6 = 30 + 6 = 36. This demonstrates that the tens digit is multiplied by 10 to get the full value in the tens place, while the units digit represents its own value.