Consider the equation y = 4.2x and the table below that represents this relationship.
A 2-column table with 4 rows. Column 1 is labeled x with entries 0, 2, 4, 6. Column 2 is labeled y with entries 0, 8.4, 16.8, 25.2.
The coefficient of the equation or constant of proportionality is

look at the picture.

y-intercept for the function on a picture is 4 → point (0, 4).

y-intercept for the function

is for x = 0. substitute:

y-intercept is 8 → point (0, 8).

to find the unit price of an object, you divide the price by object. you are trying to find out how much an object cost per unit.

for instance, lets say you have 50lb of ice cream(object) that cost 8.00 dollars(price). to find the unit cost, we take the 8.00 and divide it by 50, which will give us .16 cents per pound. we can check this by multiplying .16 by 50 = 8.00

so

object = e2

price = d2

unit price = c2

formula for c2:

=d2 / e2

so in my example about ice cream, we would have the following.

e2 = 50

d2 = 8.00

c2 formula:

=d2 / e2

-3(b-8)-5=9(b+2)+1

distribute

-3b+24-5=9b+18+1

add/ subtract

-3b+20=9b+19

20-19= 1

-3b+1=9b

9b+3b= 12b

1=12b

1 divided by 12 = 1/12

answer: 1/12 = b