Question

(5-y) whole square find coefficients of y in expansion

Answer 1

(5-y)^2=5^2+(-y)^2-2*5*y
           =5^2+y^2-10y


therefore coefficients of y in expansion are 10 and 1

Answer 2

(5-y) ² = 5² - 2*5*y + y²
=25-10y+y²

coefficient of y= 1