(1,2)(2,7)
slope = (7 - 2) / (2 - 1) = 5/1 or just 5
y = mx + b
slope(m) = 5
use either of ur points (1,2)...x = 1 and y = 2
now we sub and find b, the y int
2 = 5(1) + b
2 = 5 + b
2 - 5 = b
-3 = b
so ur equation is : y = 5x + (-3)...or it can also be written as : y = 5x - 3
