When Alyssa was ten years old, she was twice as old as her horse midnight. If midnight died when he was twenty four years old, how old was Alyssa when Midnight died?

Let Alyssa's horse's age be x .

Then :-

Alyssa's age = 2x

Age of her horse when it died = 24

Alyssa's age when her horse died =

∴ Alyssa was 48 years old when her horse Midnight died .

step-by-step explanation:

descending order means to order the polynomials from the term with the largest exponent to the term with the smallest exponent.  

therefore, the correct answer is d.