[tex] -\dfrac{3}{4}(8k-24) > -12\ \ \ \ |\teext{change the signs}\\\\\dfrac{3}{4}(8k-24) < 12\ \ \ \ |\cdot\dfrac{4}{3}\\\\8k-24 < 12\cdot\dfrac{4}{3}\\\\8k-24 < 4\cdot4\\\\8k-24 < 16\ \ \ \ |+24\\\\8k < 40\ \ \ \ |:8\\\\k < 5\to k\in(-\infty;\ 5) [/tex]
