1) The degree of polynomial 5xy - 7x²y + 8x²y² - 2x²y³ is

degree of the polynomial is 5.
as,    5x^​1y¹-7x²y¹ + 8x²y² - 2x²y3
        
       =   (1+1)  (2+1)  (2+2)  (2+3)
     degree's are  =   2 , 3 , 4 , 5
then highest degree is 5.
ans =  5