Does the following set of polynomials form a basis of p_4? (justify) {2, 2 - 3t^2, 2 - 3t^2 - 5t^3, 2 - 4t^2 - 5t^4, 2 - 4t^3 - 5t^4}

Martha is training for a duathlon, which includes biking and running. she knows that yesterday she covered a total distance of over 55.5 miles in more than than 4.5 hours of training. martha runs at a speed of 6 mph and bikes at a rate of 15.5 mph.