Answer:
a. 
b Slope:
or 
Step-by-step explanation:
The equation of a line that passes through the origin is:

Where "m" is the slope of the line.
By definition, Direct variation equations have the following form:

Where "k" is the Constant of variation.
Then, you can conclude that:

a. Let be "d" the distance in miles that the train travels per gallon.
You can observe in the graph that when the train travels 10 miles, it uses 100 gallons. Then, you can set up the following proportion:

Solving for "x", you get:

Then, it travels 0.1 miles per gallon.
b. The slope is also
or
. To check this, you can subsitute the coordinates of the point (100,10) into
and solve for "m" in order to find its value.
This is:

Answer:
-2
Step-by-step explanation:
12=2+7d
7d= -12-2
7d= -14
d= -14
-----
7
d= -2
Answer:
16=9+m m=7
Step-by-step explanation:
m=7 makes the equation true
Remmeber, you can do anything to an equation as long as you do it to both sides
for inequalities, if you multiply or divide both sides by a negive, flip the direction of the inequality sign
pemdas always applies
but also the commutative property and assiociative property
so
2(5y+13)-6<20
add 6 both sides
2(5y+13)<26
divide both sides by 2 (easier that distributing)
5y+13<13
minus 13 both sides
5y<0
y<0 is the solution
C(1;2)
a = 1
b = 2
r = 4
(x-a)² + (y-b)² = r²
(x-1)² + (y-2)² = 4²
(x-1)² + (y-2)² = 16