It will be close to 15 days but don’t take my word for it
For easier notation lets use: Nn=x and Nd=y
x+y=22
5x+10y=135
Multiply the first equation by 5 to get
5x+5y=110
Now you can eliminate x by subtracting the first equation from the second
5x+10y-5x-5y=135-110
5y=25
y=5
x=17
I think it’s binomial because the 3x^3 is one term and -6x is another
