Answer:
3
Step-by-step explanation:
f(x) = 2x^2 + 1
f(-1) means that wherever you see an x on the right hand side, you substitute -1.
f(-1) = 2(-1)^2 + 1 = 2 + 1 = 3
I believe it's 9.1 Hope this helps :)
You simply put 40 over a hundred and 55 over n (which is the number were trying to find) so you do cross multiplication. 55 times a hundred and after you get the answer. You divide it by 40 and should get 137.5.
