The first one it's the first image, and the second one is the second image.
It will take 5 days. set up the system of equations, sarah’s equation is y=2x+5, and josh’s is y=3x, the solution is 5 days.
Solve for b, since we already have the slope
y = x + b
10 = 20 + b
b = -10
y = x - 10
Hope this helps!
For the first one, 2/5 is the constant rate of proportionality because you are using it in a y=kx equation.