Which algebraic expression is a polynomial with a degree of 5?

3x5 + 8x4y2 – 9x3y3 – 6y5
2xy4 + 4x2y3 – 6x3y2 – 7x4
8y6 + y5 – 5xy3 + 7x2y2 – x3y – 6x4
–6xy5 + 5x2y3 – x3y2 + 2x2y3 – 3xy5

2xy4 + 4x2y3 – 6x3y2 – 7x4

Step-by-step explanation:

The degree of a polynomial is the highest exponent of the expression. If there is more than one variable, the degree is calculated by adding the the exponents of the variables in the term.

3x5 + 8x4y2 – 9x3y3 – 6y5  has the term x3y3 and x4y2 which is degree 6

2xy4 + 4x2y3 – 6x3y2 – 7x4  has the term x2y3 and x3y2 which is degree 5

8y6 + y5 – 5xy3 + 7x2y2 – x3y – 6x4  has the term y6 which is degree 6

–6xy5 + 5x2y3 – x3y2 + 2x2y3 – 3xy5 has the term xy5 which is degree 6

the perimeter is increased by a factor of 2