Question

What are the solutions of 3d-<-10or 2d+7>9?

Answer 1

$3d < -10\ \vee\ 2d+7 > 9\\\\(1)\qquad3d < -10\ \ \ \ |:3\\.\qquad \qquad d < -\dfrac{10}{3}\\\\(2)\qquad2d+7 > 9\ \ \ \ |-7\\.\qquad\qquad2d > 2\ \ \ \ |:2\\.\qquad\qquad d > 1\\\\Answer:\ d < -\dfrac{10}{3}\ \vee\ d > 1\to d\in\left(-\infty,\ -\dfrac{10}{3}\right)\ \cup\ (1,\ \infty)$