Answer:

Step-by-step explanation:
because you are finding the total they both had in September, you add. 12 + 9 = 21
M(CE) = 78 + 78*4/26 = 90
C. (3x+1)(3x-2) 3x times 3x= 9x^2 and 3x times -1= -3x
2 times 3x= 6x and 2 times -1= -2
9x^2- 3x+6x-2
9x^2+3x-2
Hope I explain this more clearly for you.
G(x)=-3 because f(x)=1 and you plug in 1 for X.