Exercise
$4x^2+21x-28<0$
Step-by-step Solution
Learn how to solve problems step by step online. Solve the inequality 4x^2+21x+-28<0. Use the complete the square method to factor the trinomial of the form ax^2+bx+c. Take common factor a (4) to all terms. Add and subtract \displaystyle\left(\frac{b}{2a}\right)^2. Factor the perfect square trinomial x^2+\frac{21}{4}x+\frac{441}{64}. Simplify the addition \left(x+\frac{21}{8}\right)^2-7-\frac{441}{64}.
Solve the inequality 4x^2+21x+-28<0
Final answer to the exercise
$x<\frac{\sqrt{889}-21}{8}$