(5,465)(7,625)
slope(m) = (625 - 465) / (7 - 5) = 160/2 = 80
y = mx + b
slope(m) = 80
use either of ur points (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 it in standard form
y = 80x + 65
-80x + y = 65...multiply by -1 to make x positive
80x - y = -65 <== standard form
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function notation.....f(x) is the same as y
so y = 80x + 65 in function notation becomes f(x) = 80x + 65
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x axis will be days rented
y axis will be total cost
to graph :
y = 80x + 65.....the slope here is 80...the y int is (0,65)
to find the x int, sub in 0 for y and solve for x
0 = 80x + 65
-80x = 65
x = - 65/80 = - 13/16....so ur x int is (-13/16,0)
and if u need to find more points on ur line....
80x - y = -65....sub in any number for x, and solve for y