Hey there!!
What is degree?
A degree is the highest power a variable is raised to.
(1) (x²-y)² = x⁴ + y² - 2x²y
Hence, the degree is 4
(2) 8x⁴ - 5x⁷ + 4x⁵
There are no like terms to add.
Hence, the degree is 7
(3) x²y² + 2x³ + 8x³
The first term, we have two exponents, now, we will need to add them to find their ultimate degree.
Hence, the degree is 4
(4) x⁴ + 2x³ - 6x⁴ - 17
After combining like terms:
... -5x⁴+ 2x³ - 17
Hence, the degree is 4
(5) -x² + 7x - 4x
... -x² + 3x
Hence, the degree is 2
(6) x⁷ + y⁸ + x⁷ - y⁸
... 2x⁷
Hence, the degree is 7
Hope my answer helps!