Answer:

Step-by-step explanation:
the minimum of f is for x = 1 and f(1)=0
f is decreasing for x<=1 and increasing for x>=1
so the domain is 

x>=1 so x is positive and we can take the square root
so 
You've got 3 values there.
Get the sum of 65, 30 and 25 and divide their sum by the number of values that exist, which in this case is 3.

Answer:
40
Answer:
4.80 units (3 s.f.)
Step-by-step explanation:

Hence, length of AB
= √(11+1)^2 - (8+3)^2
= √ 12^2 -11^2
= √ 23
= 4.80 units (3 s.f.)
-7-w<10
Add 7 to each side
-w<17
Change signs and flip sign
w>17
Hope this helps :)