Help?? Thanks if you do

Answer:
l = 6[tex]a^{4}[/tex] + 2a - 1
Step-by-step explanation:
the area (A) of a rectangle is calculated as
A = lw ( l is the length and w the width )
given A = 18[tex]a^{5}[/tex] + 6a² - 3a and w = 3a , then
3aw = 18[tex]a^{5}[/tex] + 6a² - 3a ( divide each term by 3a )
w = [tex]\frac{18a^{5} }{3a}[/tex] + [tex]\frac{6a^2}{3a}[/tex] - [tex]\frac{3a}{3a}[/tex] = 6[tex]a^{4}[/tex] + 2a - 1