Question

The graph below shows the cost, in

dollars, per notebook at the school store.
Which equation represents the total cost, T, per n notebooks?

Answer 1

T= 2.4n + 0

Did this for a test and that is what I put

Answer 2

t = 2.4n

Explanation:

y = mx + c

t = mn + c

c = y-intercept (where the graph line crosses the cost line)

c = 0

mx/mn= gradient ( rise/run, up/across)

mn= 12/5 ( you could have picked any point in the graph )

mn= 2.4

the m is unnecessary now so we discard it

t = 2.4n + 0