Resposta :
a) a = (12 - 3)/(5 - 1) = 9/4
(y - 12) = 9/4 *(x - 5)
4y - 48 = 9x - 45
4y = 9x + 3
y = (9x + 3)/4
(y - 12) = 9/4 *(x - 5)
4y - 48 = 9x - 45
4y = 9x + 3
y = (9x + 3)/4