It doesn’t matter which equation you decide to work with or even which variable you choose to solve for, as you should find the same solution no matter what. However, you do want to make the process as simple as possible. You should choose the equation that you think will be easiest to work with. For instance, if there is an equation where one of the coefficients is 1, such as x - 3y = 7, you would choose that as it will be easy to solve for ‘x’. For example, let’s say our equations are:  x - 2y = 10 (equation A) and -3x -4y = 10 (equation B). You would choose to work with x - 2y = 10 because the coefficient of x in this equation is 1. Solving for x in equation A would meaning adding 2y to both sides. Therefore, x = 10 + 2y. For this step, you will need to insert (or substitute) your solution for ‘x’ into the other solution that you did not work with. This will allow you to find the other variable, in this case ‘y’. Let’s try it: Insert the ‘x’ of equation B into equation A: -3(10 + 2y) -4y = 10. You can see that we have taken ‘x’ out of the equation and inserted what ‘x’ equals. Now that you have removed one of the variables from the equation, you can solve for the other variable. This is is simply solving a regular one-variable linear equation. Let’s solve ours:  -3(10 + 2y) -4y = 10 so -30 -6y -4y = 10. Combine the y’s: -30 - 10y = 10. Move the -30 over to the other side: -10y = 40. Solve for y: y = -4. To do this, plug your findings for ‘y’, or the first variable, into one of the equations. Then solve for the other variable, in this case ‘x’. Let’s try it:  Solve for ‘x’ in equation A by plugging in y = -4: x - 2(-4) = 10. Simply the equation: x + 8 = 10. Solve for x: x = 2. Plug both of the variables into each equation to make sure that they create true equations. Let’s see if ours work:  Equation A: 2 - 2(-4) = 10 is TRUE. Equation B: -3(2) -4(-4) = 10 is TRUE.
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One-sentence summary -- Begin by solving one equation for either variable. Substitute your findings in Step 1 into the other equation. Solve for the other variable. Solve the second variable. Double check that the variables you have found work for both equations.


Urine analyzers have seen it all and know to test for commercially available test-masking chemicals. Most household substances, such as bleach, salt or vinegar, will radically alter the pH of your urine, which will make it obvious that you have tampered with the sample. Diluting the sample by adding water can also raise red flags by changing the color and/or temperature of your urine; a clear sample will probably be rejected offhand, as will a lukewarm one.  Ignore the rumor going around that drinking bleach will purify your urine. Drinking bleach can corrode your mouth, throat, and stomach, potentially killing you. What's more, it won't even mask your sample. Don't fall for false advertising on products that say your test will come up negative if you add the substance to your urine. They don't work. By increasing your intake of liquids, you will be able to (somewhat) dilute the test sample. This won't work very well if you're a heavy user, but it could do the trick if you've only used a few times.  There's no special drink or ingredient that will help to "flush" your system or cleanse you any better than water does. There is no evidence that substances like goldenseal, vinegar, niacin, or vitamin C have any effect on your levels of drug metabolites.  Take some vitamin B pills the day before your test to make your urine look yellow. If it's too clear, test evaluators will be suspicious. This will help pump drug metabolites from your body. Drink a lot of water the morning of the test and make an extra effort to pee a lot before you take it.  Boost your fluid output with some sort of diuretic. This will stimulate urination and will help flush your system. Diuretics include coffee, tea, and cranberry juice. Stronger diuretics, such as furosemide, are available by prescription only. Drug metabolites build up in your body while you're sleeping, so your first stream of the day will have a higher concentration. Make sure you urinate before you have to take the sample, and drink plenty of water so your urine will be more diluted. If you aren't being watched, make sure to pee in the toilet first and then in the sample cup; your initial urine stream will contain more metabolites. This is a lot trickier than it sounds, so consider it a last-ditch attempt (and one for which you'll likely be penalized if you get caught). You can either buy fake urine or find a clean donor. The trick will be to maintain the sample at the proper temperature for the urinalysis (around 91 to 97 F) and smuggle it into the testing area. Kits containing both fake urine and the equipment needed to keep it at the right temperature can be purchased online or in smoke shops.  Synthetic urine passes most tests, but some states have started testing for uric acid. Make sure your sample has uric acid listed as an ingredient. The synthetic urine should also have a smell. Scentless urine is suspicious to test evaluators. It's essential to keep the sample at the right temperature. If the temperature is too cold or hot, it's a dead giveaway that the sample has been tampered with. Using a donor is more risky than using fake urine, because you never know what else might show up in that person's test. You can test it yourself using a test strip available at smoke shops and most drugstores. Use the sample within 48 hours, after which it gets dark in color and the pH level begins to change.
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One-sentence summary -- Don't try to mask or dilute the sample. Drink a lot of water starting the day before the test. Urinate as much as possible before the test. Consider substituting synthetic or clean urine for your own.


You can use a cast-iron skillet or any skillet that's safe to put into the oven. Then, preheat the oven while you prepare the tenderloin. Heating the skillet will help your tenderloin brown when you put it into the pan. Put on oven mitts and remove the hot skillet from the preheated oven. Set it on the stove and pour in 1 teaspoon (4.9 ml) of vegetable oil. Then, carefully swirl the pan a little so the oil spreads across the skillet. The oil will prevent the tenderloin from sticking to the hot skillet. Insert an instant-read meat thermometer into the thickest part of the tenderloin. Once it's reached at least 145 °F (63 °C), take the tenderloin out of the oven.
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One-sentence summary --
Put an oven-safe skillet into the oven and turn the oven to 450 °F (232 °C). Take the pan out of the oven and swirl vegetable oil in the bottom. Remove the pork when it reaches at least 145 °F (63 °C).