Hey there! I'm happy to help!
The equation y=0.5x simply means that Joseph is hiking 0.5 miles every hour. This is because the x value is the independent variable or the thing you change, which in this case is the time you take hiking. The distance, the y-value, is dependent on that time.
Now, let's look at Kelly's graph. This graph isn't a grid, so we will have to eyeball some of the numbers on the graph. It appears that after 10 hours, Kelly has traveled eight miles. This is because if you go up from the 10 and meet the line and then go to the left. you will be about at the line right below the 10 on the y-axis, and if you count the lines, you will see that we are counting by 2, so it has to be eight.
So, we see that Kelly takes 10 hours to go eight miles. We know that Joseph's distance is half of his time (4 hours would be 2 miles, 6 hours would be 3 hours, etc.)
So, if we say that Joseph hikes for ten hours, he will have hiked five miles as that is half of ten. We see, though, that Kelly made it eight hours in that time, so Kelly is going faster here.
Have a wonderful day and keep on learning! :D
