(3,25000) (23,68000)
slope = (68000 - 25000) / (23 - 3) = 43000/20 = 2150
y = mx + b
slope(m) = 2150
use either of ur points....(3,25000)...x = 3 and y = 25000
now we sub and find b, the y int
25000 = 2150(3) + b
25000 = 6450 + b
25000 - 6450 = b
18550 = b
so ur equation is : y = 2150x + 18550 <===