Q.Represent the solution set $-3 \le x < 4$ on the number line, describing the type of circle used at each end.

[!TLDR] The two ends of a compound inequality are marked independently, one filled and one open. [!ANSWER] Closed (filled) circle at $-3$ (included, since $\le$); open (holl …

The inequality $-3 \le x < 4$ has two different boundary types: the left end uses $\le$ (slack), so $-3$ is included and gets a closed (filled) circle; the right end uses $<$ (strict), so $4$ is excluded and gets an open (hollow) circle. The segment of the number line strictly between $-3$ and $4$ — together with the point $-3$ itself — is shaded solid, since every such value satisfies the compound …

Read the inequality symbol at each end of the compound inequality separately and choose the matching circle type …

A common error is using the same circle type (both open, or both closed) at both ends, forgetting that a compound inequality can mix a slack …