geometry
posted by sue on .
If the slope of a line is 5/3 and a point on the line is (57,12) using the given point and the slope find the coordinates of the lattice point on the line?

The "pointslope" form of the equation of a straight line is:
y  y1 = m ( x  x1 )
(x1, y1) is a known point
m is the slope of the line
(x, y) is any other point on the line
In this case:
m = 5 / 3 , x1 = 57 , y1 = 12
y  12 = ( 5 / 3 ) (x  57 )
y = (5 x / 3 )  ( 5 * 57 / 3 ) + 12
y = (5 x / 3 )  ( 285 / 3 ) + 12
y = (5 x / 3 )  95 + 12
y = (5 x / 3 )  83