Answer
a) $\left[-10,6\right]$.
b) $(-\infty,-4]\cup[0,\infty)$.
Work Step by Step
Part a.
From the graph, the values of $x$ that satisfy the inequality $y\leq4$ are in the interval $\left[-10,6\right]$.
Part b.
From the graph, the values of $x$ that satisfy the inequality $y\geq1$ are in the interval $(-\infty,-4]\cup[0,\infty)$.
