4x - 9 ≥ -21 on a number line
To graph the inequality 4x - 9 ≥ -21 on a number line, we first need to solve for x:
4x - 9 ≥ -21
4x ≥ -21 + 9
4x ≥ -12
x ≥ -3
Now, we plot a closed circle at -3 on the number line (since the inequality includes "greater than or equal to"). Then, we shade to the right of -3 to show that all values of x greater than or equal to -3 satisfy the inequality.
The graph should show an arrow extending to the right from the closed circle at -3.