(a)[1]
Write down an expression in terms of x for the time Martha spends walking.
(b)[4]
Show that $7x^2-2x-80=0$.
(c)[3]
Solve $7x^2-2x-80=0$, giving your answers correct to 2 decimal places. Show all your working.
(d)[3]
Calculate the difference between Martha’s walking time and her running time. Give your answer in hours and minutes to the nearest minute.