Exeter Math Solutions / Explanations

I'm a math tutor and one of my students is working through Phillips Exeter Mathematics 4-5 (Calculus). I'm looking for answers / answer explanations or any kind of companion resource for the Exeter problems: https://www.exeter.edu/sites/default/files/documents/Math4_2022_Printed.pdf But I can't seem to find anything online. If anyone can point me to resources I would be endlessly grateful!