Write a wrapper function named bexpand that takes three

Question

Note: This is a scheme programming language task,

Please don't give answer if you don't know about anything. Please write what is asked.

Question: Write a wrapper function, named b­expand, that takes three arguments: two variable names (such as x and y), and a number n. N represents the highest exponent in the expanded list, as well as the row number from pascal's triangle. The row containing ‘(1) in pascal's triangle is the zero­th row.