a. x4 : xn = x4 - n
b. xn : x5 = xn - 5
c. \(\left(3x^4y^3+\dfrac{1}{2}x^3y^2+x^5y\right):4x^ny^n\)
= \(3x^4y^3:4x^ny^n+\dfrac{1}{2}x^3y^2:4x^ny^n+x^5y:4x^ny^n\)
= \(\dfrac{3}{4}x^{4-n}y^{3-n}+\dfrac{1}{8}x^{3-n}y^{2-n}+\dfrac{1}{4}x^{5-n}y^{1-n}\)
a: \(x^4:x^n=x^{4-n}\)
b: \(x^n:x^5=x^{n-5}\)