Question

I REALLY NEED HELP PLEASE!!  

Mark is observing the velocity of a runner at different times. After one hour, the velocity of the runner is 6 km/h. After three hours, the velocity of the runner is 2 km/h. Part A: Write an equation in two variables in the standard form that can be used to describe the velocity of the cyclist at different times. Show your work and define the variables used. (5 points) Part B: How can you graph the equations obtained in Part A for the first 5 hours? (5 points)

I really need to finish this today please help!!

Answer 1

part A)


`\bf \begin{array}{ccllll} hours(x)&velocity(y)\\ -----&-----\\ 1&6\\ 3&2 \end{array}\\\\ -------------------------------\\\\`






`\bf y-{{ y_1}}={{ m}}(x-{{ x_1}})\implies y-6=-2(x-1)\\ \left. \qquad \right. \uparrow\\ \textit{point-slope form} \\\\\\ y-6=-2x+2\implies y=-2x+2+6\implies \boxed{y=-2x+8}`

part B)

well, we know y = -2x+8.... so.. what's the runner's velocity after 5hours? well, x = 5, thus y = -2(5) +8 ---> y = -2

to graph it, well, is a LINEar equation, meaning the graph is a LINE, and to graph a line, all you need is two points, and by now, you have more than two.. so graph it away.