Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
Answer:
See below
Step-by-step explanation:
Assuming a number line:
rs + st = rt
3x-16 + 4x-8 = 60
7x -24 = 60
7x = 84
x = 12
The linear function that models the total cost for x deliveries is:

-------------------
A linear function has the following format:

In which
- m is the slope, that is, the rate of change.
- b is the y-intercept, that is, the value of y when x = 0.
In this problem:
- Fixed cost of $9 per month,
. - Cost of $2 for each delivery, thus
.
The function for the <u>total cost for x deliveries is:</u>

A similar problem is given at brainly.com/question/16270359
Answer:
The linear function with the smallest slope must be multiple of one of the other two linear functions if all functions are coplanar. Otherwise, they intersect at the given point in space.
Step-by-step explanation:
A system of two linear functions with two variables have an unique solution on a given plane, as there are three linear function, it means that linear function with the smallest slope must be multiple of one of the other two linear functions.
But, if those functions are not all coplanar and have 3 variables, they intersect at the given point.
Answer:
164
Step-by-step explanation:
2x+7+5x+12=180
7x+19=180
7x+180-19
7x=171
---- ----
7 7
x=164