Answer:
The solution set of x^2 + 4x - 21 ≤ 0 is (-7, -3)
Explanation:
To solve this inequality, we first set x^2 + 4x - 21 = 0 and factor it to get (x + 7)(x - 3) = 0. This gives us x = -7 and x = 3 as the solutions.
To find the solution set of x^2 + 4x - 21 ≤ 0, we need to determine the values of x that make the expression on the left-hand side non-positive. Since x^2 + 4x - 21 is a quadratic function, it is non-positive when x is less than -3 or x is greater than -7.
Therefore, the solution set of x^2 + 4x - 21 ≤ 0 is the set of all x such that x ∈ (-7, -3).