Write an equation in point-slope form of the line that passes through the given point and with the given slope m. (-3,1), m=7

y-1=7(x+3)

Step-by-step explanation:

point slope form is y-y1=m(x-x1)

it is decreasing in the time interval 0<x<2 hours.

Step-by-step explanation:

Graph of first line going through ordered pairs A(0, 40) and B(2, 10).

Graph of second line going through ordered pairs B(2, 10) and C(4, 10). Graph of third line going through ordered pairs C(4, 10) and D(7, 50).

When movement is from point A to B, change in x = 2 and change in y = -30

Hence change for unit x = -30/2 = -15 ... i

When movement is from point B to C, change in x = 2 and change in y = 0

Hence change for unit x = 0/2 = 0 ... ii

When movement is from point C to D, change in x = 3 and change in y = +40

Hence change for unit x = 40/7 = 5.71  .. iii

Hence from A to B it is decreasing, B to C it remains constant and C to D it is increasing.

x coordinate represents hours and y coordinate degrees.

Hence answer is it is decreasing in the time interval 0<x<2 hours.