Answer:
f(x) = -(x-4)^2 + 5
Step-by-step explanation:
The function 
is a quadratic function. Its graph looks like a parabola. The graph has a vertex of (4,5) and opens up downward.
Proving that 
for all x:
Answer:
The answer is A
If x = 0 then y = 1
Step-by-step explanation:
None? Unless the second option is supposed to be 10^2 or the fourth option is 50 x 2.
2798 divided by 20 equals 139.9
Answer:
40 Km
Step-by-step explanation:
Cross-multiply (rule of three)
2.5 cm--------10 Km
10 cm-----------x Km
2.5/10 = 10/x
so
x = 100/2.5 = 40 Km
