Respuesta :

Use the points (1, 15000) and (8, 1000) for the slope of the trendline

m = (1000 - 15000)/(8 - 1) = (-14000)/7 = -2000

y = -2000x + b
15000 = -2000(1) + b
15000 = -2000 + b
17000 = b

Equation
y = -2000x + 17000