3 GBs per month because you have to take 30-21 (the monthly cost of the phone)=9 and each GB is $3 a month so 9 divided by 3= 3
It’s A 44-1) and if not then it’s b
The x² term will be C(5,2)x²·2³ = 80x².
The coefficient is 80.
_____
C(n, k) = n!/(k!·(n-k)!)
C(5, 2) = 5·4/(2·1) = 10