Make sure you draw it according to any required specifications. If your number line has no specifications, just make sure to include positions for both x{\displaystyle x} values your found previously. Include a few values above and below these to make the number line easier to interpret. For example, since the roots for the inequality x(x+4)<21{\displaystyle x(x+4)<21} are x>−7{\displaystyle x>-7} and x<3{\displaystyle x<3}, draw a number line that includes positions for -7 and 3. Plot the points by drawing a circle over their position on the number line. If the inequality is greater than (>{\displaystyle >}) or less than (<{\displaystyle <}), draw an open circle. If the inequality is greater than or equal to (≥{\displaystyle \geq }) or less than or equal to (≤{\displaystyle \leq }), fill in the circle on the number line, since the values are included in the set. For example, since the roots your are working with are x>−7{\displaystyle x>-7} and x<3{\displaystyle x<3}, you would draw open circles at the -7 and 3 positions on the number line. If x{\displaystyle x} is greater than the value, draw a line pointing to the right on the number line, since the included values will be larger than x{\displaystyle x}. If x{\displaystyle x} is less than the value, draw a line pointing to the left on the number line, since the included values will be less than x{\displaystyle x}. If the included values are between two numbers, you will draw a line between the two plotted points. For example, since you want to show that x>−7{\displaystyle x>-7} but also x<3{\displaystyle x<3}, you need to draw a line between -7 and 3 on the number line.
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One-sentence summary -- Draw a number line. Plot the x{\displaystyle x} values on the number line. Draw arrows or lines indicating the included values.

Article: The essential tool for following a juice-based diet is a juicer.  You can purchase either a cold press juicer (also known as an Auger-style juicer) or a juice extractor.  Juicers can vary widely in price (anywhere from $50 to over $400) and come in a variety of sizes.  An Auger-style or cold press juicer are typically more expensive.  They work by slowly crushing and mashing fruits and vegetables to extract the juice.  The advantages of this style of juicer is that they typically leave behind more pulp in the juice.  The pulp is from the skin and other fibrous parts of the fruit or vegetable and can add a little boost of fiber to your juices.  The down side of these juicers is that they can easily get jammed with tougher fruits or vegetables.  A juice extractor separates the juice from the pulp and filters the juice through a strainer so no pulp remains.  All fruits and vegetables should be cleaned and peels/skins removed as these can jam the machine.  The disadvantage to juice extractors is that they can be hard to clean.  Review a variety of brands and types of juicers before making your purchase.  Look for features that make the machine easy to use, store and clean.  For example, find a juicer that has parts that are dishwasher safe or has a large feeding chute to allow for bigger slices/chunks of food. Also consider purchasing a blender. Blenders also vary in size and price and allow you to process the entire fruit or vegetable.  Unlike juicers, blenders allow you to consume the entire fruit – including the fiber containing pulp and skins/peels.  If your juice becomes too thick, add water to thin it out to your desired consistency. Many juicers are expensive and not in everyone's budget.  If you're still interested in following a juicing diet, try purchasing fresh 100%  juice instead of making it yourself.  Avoid purchasing frozen fruit concentrate or fruit juice cocktails.  These types of juices typically have added sugars, flavorings and preservatives that are not healthy. Outside of your grocery, there are some juice bars and markets that sell a variety of freshly pressed fruit and vegetable juices.  You can purchase a single serving or large quantities. Another essential ingredient to following a juicing diet is to have a variety of fruits and vegetables on hand.  Purchasing both fresh and frozen items will give you more flexibility and variety with your juices.  As a rule, your juice should be 2/3 vegetables and 1/3 fruit. Fruits generally contain a lot of sugar, which can cause your blood sugar to spike. Buying frozen fruits or vegetables allows you to stock up on items that might be out of season.  In addition, you can use a small portion of frozen items in one sitting without worry of them going bad. Mixing both frozen and fresh items together can give you thicker smoothie-like consistency to your juice which may be more enjoyable. Be careful to only buy frozen fruits and vegetables without added sugars.  Read the ingredient labels to make sure only the fruit or vegetable is listed. Before purchasing a large quantity of fruits and veggies, try making a few small servings of different blends of juices.  This will prevent you from wasting items you may not enjoy as a juice.  Many times, when you purchase a juicer or blender, the company provides you with a small recipe book to use.  This is a good place to get quick ideas for recipes. Note that when making your own fresh juice, it takes a significant amount of fruits or vegetables to make enough juice.  For example, it takes 6-8 large carrots to make 1 cup of juice.  Make sure to wash all your fruits and veggies first.  This is especially important when you're going to blend the skin/peels into your drink. Follow the juicer's instruction booklet.  Most recommend to add delicate items first (like leafy greens), followed by softer items (like a banana or tomato) and add hard foods (like carrots or apples) last. Freshly squeezed or processed juices are more susceptible to harmful bacteria which can make you sick.  Prepare your juice for one day at a time.  Keep and store all juice in an airtight container for no longer than 24 hours.  Make sure to keep all freshly processed juice in the refrigerator so it stays within the acceptable temperature range of below 40 F.  Purchase small, air-tight water bottles or mason jars to help you store smaller quantities of juice safely in the refrigerator.  Mason jars also make a great on-the-go container.
Question: What is a summary of what this article is about?
Buy a juicer. Buy fresh, 100% juice. Buy a variety of fruits and vegetables. Prepare sample juices. Prepare only 1-2 servings of fresh juice at a time.