Is the relationship shown by the data linear? if so, model the data with an equation. x y –9 –2 –5 –7 –1 –12 3 –17

Yes its linear because the x values increase by a constant value 4 and the y values by a constant value -5.

one general form for a linear equation is

y - y1 = m(x - x1)      m = slope and (x1,y1) is a point on the line

from the data the slope iis  (-7-(-2)) /  (-5-(-9)  =  -5 / 4

so using the point (3, -17):-

y - (-17) = (-5/4) ( x - 3)

y + 17 = -5x/4 + 15/4

4y + 68 = -5x + 15

4y = -5x - 53  

thats the equation of the line

The answer is 225 miles per 4.5 hours. hope this ; )