Question

Solve each inequality. Then graph it on a number line.

$p-4<-7$

Short answer

The required value of x is $\left(-\infty ,-3\right)$. The graph on the number line is,

Step-by-step solution

Step 1. State the concept for inequality.

To graph the endpoint with strict inequality < or >, use the open parenthesis or a hollow circle at that endpoint.

To graph the endpoint with inequality symbol $\le \text{or}\ge$, use the bracket or a solid circle at that endpoint.

Properties of inequality:

$$\begin{gathered} 1.b\le c\Rightarrow b\pm a\le c\pm a \\ 2.b\le c\Rightarrow ab\le ac,\text{if}a>0 \\ 3.b\le c\Rightarrow ab\ge ac,\text{if}a<0 \end{gathered}$$

Step 2. Solve the inequality for x.

In order to solve the inequality:

$p-4<-7$

Add 4 both sides of the inequality, as

$$\begin{gathered} p-4<-7 \\ p-4+4<-7+4 \\ p<-3 \end{gathered}$$

Thus, the solution of the given inequality is every number is strictly less than $-3$, this can be represented in the interval form, as width="69">−∞,−3.

Step 3. Plot the graph on the number line.

Now, in order to sketch the graph of the solution of the inequality, since the interval of solution at left end point $-3$is strict, so use a hollow circle at point $-3$. And the solution interval at left endpoint $-\infty$, thus every point strictly less than $-3$is in the solution interval of given inequality. The graph of the solution of inequality is shown below: