The sum of arithmetic series is given by:
Sn=n/2(a1+an)
where:
n=number of terms
a1=first term
an=nth term
but
n=18, an=275, Sn=4185
plugging the values in the formula we get:
4185=18/2(a1+275)
simplifying this we get:
4185=9(a1+275)
dividing through by 9 we get:
465=a1+275
thus
a1=465-275
a1=190
Answer: first number is 190
Scenarios B, D, and F require a police officer. In scenario B, 1:00-2:00pm, and scenario F, 5:00-6:00pm, there are 24 cars. In scenario D, 3:00-4:00pm, there are 21 cars. Both 24 and 21 are greater than 17, so a traffic officer is needed. However, in other scenarios, the number of cars are all less than 17, and no officer is needed.
Answer:

Step-by-step explanation:
A line is a one-dimensional figure that has no thickness and extends infinitely in both directions.
A line segment is a line that has two end-points and a ray is a line that has one end-point.
Given equation is 
To find : a line that lies entirely in the set defined by the given equation.
Solution:
Take 
Check:

Therefore,
satisfy the given equation.
Answer:
The answer to your question is: y = -8/3 x - 11
Step-by-step explanation:
A (-6, 5)
B (-3, -3)
Process
1.- Find the slope of the line
Formula

Substitution

Simplifying

2.- Find the equation of the line
Formula
( y - y1) = m(x - x1)
Substitution
( y + 3) = -8/3 (x + 3)
Simplifying
y + 3 = -8/3 x - 8
y = -8/3 x - 8 - 3
y = -8/3 x - 11
Answer: y = 3x + 60
<u>Step-by-step explanation:</u>
Set up two equations and solve the system:
270 = 70x + b
- <u>(150 = 30x + b)</u>
120 = 40x
3 = x
Input "x" into one of the equations and solve for "b":
150 = 30x + b
150 = 30(3) + b
150 = 90 + b
60 = b
Equation: y = 3x + 60
This means that there is a flat fee of $60 plus a rate of $3 per student