X² + 3x < 28
x² + 3x - 28 < 0
(x+7)(x-4) < 0
the zeros will be at x = -7 and x =4
∴ the solution of inequality
x ∈ (-7,4)
See the attached figure
x² + 3x - 28 < 0
(x+7)(x-4) < 0
the zeros will be at x = -7 and x =4
∴ the solution of inequality
x ∈ (-7,4)
See the attached figure