A plumber charges $45 for a service call, plus $70/h for her time.

a. Find the cost of a two hour service call.

b. How long was a services call that cost $150?

Also .......

as the weight held by a spring increases, the length of the spring increase proportionally. suppose a 2-lb weight stretches a spring to 15 in., and a 12-lb weight stretches the same spring to 20 in. what is the length of the spring with no weight attached?

a. cost=45+70*2=45+140=$185

b. $150-$45=$105 $105/$70=1.5 hrs

sooka my dik

sook me hary bllz

slope of the line through A(2, 6) and B(8, -1)?

To find the cost of a two-hour service call, we need to consider both the service call fee and the hourly rate. Here's how you can calculate it:

a. Multiply the hourly rate by the number of hours: $70/hour * 2 hours = $140.
Add the service call fee to the result: $140 + $45 = $185.
Therefore, the cost of a two-hour service call is $185.

To determine the length of a service call that cost $150, we’ll need to divide the total cost by the plumber's hourly rate:

b. Subtract the service call fee from the total cost: $150 - $45 = $105.
Divide the remaining cost by the hourly rate to determine the number of hours: $105 / $70/hour = 1.5 hours.
Therefore, a service call that costs $150 lasted 1.5 hours.

Now, let's move on to the question about the spring:

If the length of the spring increases proportionally as the weight held by the spring increases, we can use this relationship to deduce the answer.

Let's set up a proportional equation using the given information:

Length of spring (in inches) / Weight of the attached object (in lbs) = Length of spring with no weight attached (in inches) / 0 lbs

Now, we can substitute the values from the problem:

15 inches / 2 lbs = Length of spring with no weight attached / 0 lbs
20 inches / 12 lbs = Length of spring with no weight attached / 0 lbs

Since any number divided by 0 is undefined, we cannot solve directly. However, we can observe that the relationship between weight and length of the spring is linear.

By finding the slope (rate of change) of this linear relationship, we can determine the length of the spring with no weight attached.

The slope can be found by calculating the change in length over the change in weight:

(20 inches - 15 inches) / (12 lbs - 2 lbs) = 5 inches / 10 lbs = 0.5 inches per lb

To find the length of the spring with no weight attached, we can simply multiply the slope by 0 (since there is no weight):

0.5 inches per lb * 0 lbs = 0 inches

Therefore, the length of the spring with no weight attached is 0 inches.

a. C = 45 + 70*1 = $115 = Cost.

b. 45 + 70X = $150,
70X = 150 - 45 = 105,
X = 1.5h.

Jessica, check your 4-18-11,2:45pm post