Answer:
About 947 hours, walking at 5 km (3 miles)/hour.
Walking 8 hours /day [at that pace you would need to be an Olympic Athlete to keep up the pace] it will take about four months.
Walk slower, it will take longer.
Answer:
y=-3/2x+6
Step-by-step explanation:
You can find the slope by taking two points on the graph, and making the one that occurs earlier in the graph (from left to right) the first point (x1, y1) and the one that occurs later in the graph the second point (x2, y2). The equation is m (or slope)=(y2-y1)/(x2-x1). I took the first two points in the table for this. m=(12-18)/-4-(-8)
the double negative on the bottom becomes an addition=> (12-18)/(-4+8)
the top simplifies to be -6 and the bottom simplifies to 4=>-6/4
this fraction can be reduced to -3/2, which is the slope of the graph.
Now, use point slope form (y-y1=m(x-x1)) to find the equation of the graph. Plug any coordinate on the graph in for x1 and y1 here. It should be correct as long as it is a point on the graph, but I am using the point (-8, 18) here.
=>y-18=-3/2(x-(-8))
the double negative in the parentheses becomes a positive=> y-18=-3/2(x+8)
distribute the -3/2 to every term in the parentheses=> y-18=-3/2x-12
add 18 to both sides, cancelling out the -18 on the left side of the equation=>y=-3/2x+6 (-12+18=6 to get 6 for b).
Therefore, the equation is y=-3/2x+6
Answer:
For the first 30 minutes, we will have a line with a given steepness, this will represent the 30 minutes riding at a fast pace.
Then he stops for 20 minutes, we will represent this with a constant line.
Then he again moves for another 30 minutes, but with a slower pace than in the first 30 minutes, then this line will be less steep than the first line.
A sketch of this situation can be seen below.

multiplying both sides by x^2

simplifying

dividing by 7