(5,465)(7,625)
slope = (625 - 465) / (7 - 5) = 160/2 = 80
y = mx + b
slope(m) = 80
(5,465)...x = 5 and y = 465
now we sub and find b, the y int
465 = 80(5) + b
465 = 400 + b
465 - 400 = b
65 = b
equation is : y = 80x + 65...but we need standard form
y = 80x + 65
-80x + y = 65
80x - y = -65 <== standard form
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function notation : f(x) = 80x + 65
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y = 80x + 65
slope is 80
y int = (0,65)
x int can be found by subbing in 0 for y and solving for x..
0 = 80x + 65
-80x = 65
x = -65/80 reduces to - 13/16...so x int is (-13/16,0)