well, according to my work, and from looking at the previous answer as backup to my own, i did this, first i took the coordinates 7 and 3, 7 being x and 3 being y, and entered them into the equation, 2(7) - 3(3) + c = 0, then i multiplied them and moved 0 to the other side of the equation by subtracting it. 14 + (-9) = -c, then added, 5 = -c then divided by -1 to get rid of the negative variable, which i ended with -5 = c, i hope this was helpful, and the previous answer was incorrect i believe because it is negative 5 and not just 5, correct me if i am wrong, thank you :)