Solving Quadratic Inequalities Step-by-Step

Published on April 30, 2026

Algebra

Learn how to solve various quadratic inequalities with detailed step-by-step explanations, including finding roots and testing intervals.

Question

resuelve paso a paso la inecuaciones de segundo grado en la imagen adjunta

Answer

Here are the step-by-step solutions for each inequality:
a)
  1. Find the roots of the quadratic equation .
    We can factor this as .
    The roots are and .
  2. Determine the intervals.
    The roots divide the number line into three intervals: , , and .
  3. Test a value from each interval.
    • For , let’s pick : .
    • For , let’s pick : .
    • For , let’s pick : .
  4. State the solution.
    Since the inequality is $ > 0$, we want the intervals where the expression is positive.
    The solution is .
b)
  1. Find the roots of .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ > 0$.
    The solution is .
c)
  1. Find the roots of .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ \ge 0$. We include the roots because of the “equal to” part.
    The solution is .
d)
  1. Find the roots of .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ < 0$.
    The solution is .
e)
  1. Find the roots of .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ < 0$.
    The solution is .
f)
  1. Find the roots of .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ \le 0$. We include the roots.
    The solution is .
g)
  1. Find the roots of .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ \le 0$. We include the roots.
    The solution is .
h)
  1. Find the roots of .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ \ge 0$. We include the roots.
    The solution is .
i)
  1. Find the roots of .
    Multiply by -1 to make the leading coefficient positive: .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ \ge 0$. We include the roots.
    The solution is .
j)
  1. Find the roots of .
    Multiply by -1: .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ > 0$.
    The solution is .
k)
  1. Find the roots of .
    Multiply by -1: .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ < 0$.
    The solution is .
l)
  1. Find the roots of .
    Multiply by -1: .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ \ge 0$. We include the roots.
    The solution is .
m)
  1. Find the roots of .
    Multiply by -1: .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ \le 0$. We include the roots.
    The solution is .
n)
  1. Find the roots of .
    Multiply by -1: .
    Factoring gives .
    The roots are and .
  2. Determine the intervals.
    The intervals are , , and .
  3. Test a value from each interval.
    • For , let : .
    • For , let : .
    • For , let : .
  4. State the solution.
    The inequality is $ < 0$.
    The solution is .