Question

solve the inequality and graph the solution.
20 - d > 12
to draw a ray, plot an endpoint and select an arrow. select an endpoint to change it from closed to open. select the middle of the ray to delete it.

Explanation:

Step1: Subtract 20 from both sides

$$\begin{align*} 20 - d - 20&>12 - 20\\ -d&>-8 \end{align*}$$

Step2: Multiply both sides by - 1 and reverse the inequality sign

When we multiply or divide an inequality by a negative number, the direction of the inequality sign changes. So, multiplying $-d > - 8$ by $-1$ gives $d < 8$.

Answer:

The solution of the inequality \(20 - d>12\) is \(d < 8\). On the number - line, we plot an open circle at \(d = 8\) (because \(8\) is not included in the solution set) and draw an arrow to the left (towards the smaller numbers).