The degree of the polynomial obtained when 8−6x+x2−7x3+x5 is subtracted from x4−6x3+x2−3x+1 is
5
(x4−6x3+x2−3x+1)−(x5−7x3+x2−6x+8)
=x4−6x3+x2−3x+1−x5+7x3−x2+6x−8
=−x5+x4+x3+3x−7
Degree of the polynomial(that contains only one variable) is the highest exponent of its various terms. The terms of the polynomial obtained are x5, x4, x3, 3x and 7. Here, the term x5 has the highest exponent for the variable x and hence the degree of the given polynomial is 5.