Algebra-2

Question Analysis
This problem assesses the student's ability to apply Descartes' Rule of Signs to determine the possible number of positive real roots of a polynomial.

Key Concept Explanation
According to Descartes' Rule of Signs, the number of positive real roots is equal to the number of sign changes in the sequence of coefficients, or less than that by a multiple of 2.

Step-by-step Solution
1. Identify the sequence of coefficients: 5, -3, 2, -7, 4
2. Count the si...