Hello!

First we will get the variable in the correct side.
add 4c to 7c.
Second thing you will do is subtract 12 from 78
Now, divide 66 by 11 and you'll be left with c=6
Use the slope formula
Plug in the appropriate cords into the formula.
The slope of the line is -9/14.
Hi!!!!!!!!!!!!!!!!! Hope I help!
The correct answer is.............................
10^10^10! I think hope so