Answer:
see the explanation
Step-by-step explanation:
we have
closed circle on 2 to closed circle on 6
That means -----> All real numbers greater than or equal to 2 and less than or equal to 6
In interval notation is ------> [2,6]
In set builder notation is ----> { x ∈ R | x ≥ 2 and x ≤ 6 }
9/10....................................
step 1
find the equation of the line
where
x-------> numbers of light bulbs
y-------> the total cost in $
let
A (0,0) B (10,18)
slope m=18/10-----> m=1.8
step 2
with m=1.8 and the point A (0,0)
y-y1=m*(x-x1)------> y=1.8x
step 3
for x=1
y=1.8*1------> y=$1.8
therefore
the answer is
the cost of a single light bulb is $1.8
