A state department of public safety added 13x2 + 5x miles of highway to connect CoolTown and Bragville. It cost the department 3x2 – 9x thousand dollars to complete each mile of interstate. Which expression shows the total cost, in thousands of dollars, of creating this highway?

A) x4 + 12x3 – 45x2
B) x4 – 45x2
C) x4 + 15x3 – 48x2
D) 9x4 – 12x3 – 45x2

x> 6

step-by-step explanation:

8x+8> 7x+14

8x-7x> 14-8

x> 6

55.44 inches

step-by-step explanation:

part a. assuming a perfectly linear relationship, we can find the slope from the first two data points.

slope = m = (change in rainfall)/(change in years)

= (61.80 -62.33)/(2005 -2004) = -0.53/1 = -0.53

then the point-slope form of the equation of the line can be written as

y = m(x -h) +k . . . . . m = -0.53, (h, k) = (0, 62.33)

y = -0.53x +62.33 . . . x = years after 2004

part b. in 2017, x = 2017 -2004 = 13. then the predicted rainfall is

y = -0.53·13 +62.33 = 55.44 . . inches

the predicted rainfall in 2017 is 55.44 in.