Answer:
Step-by-step explanation:
Suppose the electrician spends t hours at the house working.
Amount charged for every house call by electrician = $50
The electrician earned a total of $400 for a 5 hour job.
Also, C denotes total cost of the electrician's services.
So, the equation for C in terms of t is given below.
Here,
we are given
we can check each options
option-A:
-1,1
we can plug x=-1 and x=1 and check whethet f(x)=0
At x=-1:
At x=1:
so, this is TRUE
option-B:
0,1
we can plug x=0 and x=1 and check whethet f(x)=0
At x=0:
At x=1:
so, this is FALSE
option-C:
-2,-1
we can plug x=-2 and x=-1 and check whethet f(x)=0
At x=-2:
At x=-1:
so, this is FALSE
option-D:
-1,0
we can plug x=-1 and x=0 and check whethet f(x)=0
At x=-1:
At x=0:
so, this is FALSE
Answer:
About 4 hours.
Step-by-step explanation:
Let's set up a proportion and cross multiply.
Cross multiply.
120 = 28x
Divide by 28 on both sides.
= 4.28571428571
Round this to the nearest whole number, which is just 4. The answer is about 4 hours.