INPUT ARTICLE: Article: Solving a system of equations by addition is ideal when you see that both equations have one variable with the same coefficient with opposite charges. For example, if one equation has the variable 3x and the other has the variable -3x, then the addition method is ideal. Write one equation above the other by matching up the x and y variables and the whole numbers. Write the addition sign outside the quantity of the second system of equations. Ex: If your two equations are 3x + 6y = 8 and x - 6y = 4, then you should write the first equation over the second, with the addition sign outside the quantity of the second system, showing that you'll be adding each of the terms in that equation. 3x + 6y = 8 +(x - 6y = 4) Now that you've lined up the two equations, all you have to do is add the like terms. You can take it one term at a time: 3x + x = 4x 6y + -6y = 0 8 + 4 = 12 When you combine it all together, you get your new product: 3x + 6y = 8 +(x - 6y = 4) = 4x + 0 = 12 Once you've eliminated one of the variables by getting a term of 0 when you subtract variables with the same coefficient, you should just solve for the remaining variable by solving a regular equation. You can remove the 0 from the equation since it won't change its value. 4x + 0 = 12 4x = 12 Divide 4x and 12 by 3 to get x = 3 Now that you know that x = 3, you just have to plug it into one of the original equations to solve for y. It doesn't matter which one you choose because the answer will be the same. If one of the equations looks more complicated than the other, just plug it into the easier equation. Plug x = 3 into the equation x - 6y = 4 to solve for y. 3 - 6y = 4 -6y = 1 Divide -6y and 1 by -6 to get y = -1/6 You have solved the system of equations by addition. (x, y) = (3, -1/6) To make sure that you solved the system of equations correctly, you can just plug in your two answers to both equations to make sure that they work both times. Here's how to do it: Plug (3, -1/6) in for (x, y) in the equation 3x + 6y = 8. 3(3) + 6(-1/6) = 8 9 - 1 = 8 8 = 8 Plug (3, -1/6) in for (x, y) in the equation x - 6y = 4. 3 - (6 * -1/6) =4 3 - - 1 = 4 3 + 1 = 4 4 = 4

SUMMARY: Write one equation above the other. Add like terms. Solve for the remaining term. Plug the term back into the equation to find the value of the first term. Check your answer.

In one sentence, describe what the following article is about: This button is a number (reflecting the number of tabs you have open) inside of a square and is located in the upper right corner between the search bar and the menu button. The mobile Chrome app does not support multiple windows, only tabs. Tablets will display tabs similarly to the desktop interface and will not use the tab display button. Alternately, you can open the Settings menu (vertical ellipses) after opening tab display and select "Close All Tabs" from the list. If you turn off the screen (power button) with an incognito tab open, you will see a "Close Incognito Tabs" notification when turning the screen back on. Double tap this notification and you will be returned to the home screen with all incognito tabs closed. Incognito tabs can also be closed using the same methods as regular tabs.
Summary: Tap the tab display button. Tap the 'x' icon in the upper right corner of a tab to close it. Close all tabs at once. Close Incognito tabs from the homepage (Android only).

INPUT ARTICLE: Article: Grime and dirt is sometimes the only thing holding a stone in place, especially if it is an older piece of jewelry. Use care when scrubbing and always polish while holding directly over a towel, never over a sink or floor. If a piece of the jewelry is loose, take it to a jeweler to be fixed before cleaning it on your own. Pour one cup of warm water and cup of ammonia into a bowl. Do not put the diamonds in the mixture directly. Instead, take a soft toothbrush toothbrush and dip it into the mixture. To clean other gemstones, like rubies and sapphires, use two cups of water and a few drops of dish soap or detergent. Put the jewelry into the mixture. Allow the jewelry to soak for twenty minutes before removing. You can also use baby shampoo in place of soap or detergent. Begin gently scrubbing the diamonds with the toothbrush that has been dipped into the mixture. Along with cleaning the main parts of the jewelry, make sure to to get into the small areas and setting as well. If you are cleaning diamonds with a platinum setting, this mixture with ammonia will clean the setting as well as the diamonds. Use a soft toothbrush that will not be used again for any other purpose outside of cleaning. Rinse the jewelry under or in warm water when you have finished scrubbing. If you're cleaning multiple pieces of jewelry, rinse each piece individually. Then, lay the diamonds or gemstones on a tissue to dry. Store them in a safe place once they have finished drying.. If the jewelry doesn't come out as polished as you'd like it be, you can purchase a commercial jewelry cleaner. A cleaner can be purchased online or at a jewelry store. Make sure to ask a jeweler if your jewelry can withstand a commercial cleaner before using it. The directions for using a commercial jewelry cleaner depends on the type of cleaner you have. Read the instructions carefully before use.

SUMMARY:
Examine for loose prongs. Create a mixture of warm water and ammonia for diamonds. Mix warm water and soap for gemstones like rubies and sapphires. Scrub with a soft toothbrush. Rinse with warm water. Clean with a commercial jewelry cleaner.