Your equation would be like this:
y=11x+300
because 11 depends on 'X" how many miles he walks and then just add 300 to that because that is the fixed amount
I hope I've helped!
We can just substitute y = 4x+1 in the second equation.

We know the value of x, substitute x in any equations to get the y-value.

The value of y is 3 and the value of x is 0.5 aka 1/2
Since you want the solution as a point then It's below here.
Finding gradient:
m = y2 - y1
x2 - x1
= -1 - 6
1 - 3
= -7 / (-2)
= 7/2
y = m(x - x1) + y1
y = 7(x - 3) + 6
2
2y = 7x - 21 + 12
2y = 7x - 9
You could do x=81 with the little line on the top (represents the number going on forever, and example is 0.818181818181818181818181818818181818 etc.)