 So remember, we can multiply both sides of an equation by any amount. If our equation has fractions, we can multiply through by the denominators to eliminate the fractions. And if our equation has decimals, we can multiply through by a power of 10. And the thing to remember is that multiplying by 10 will move the decimal point one place to the right. For example, let's try to solve 2.57y equals 5 plus 1.3y. So our decimals are 2.57 and 1.3. So remember, multiplying by 10 will move the decimal one point to the right. And since one of our numbers, 2.57, has two digits after the decimal point, we need to move our decimal point to places. And so to eliminate the decimals, we need to multiply by 100. So multiplying both sides by 100, then expanding gives us a new equation without any decimals. And at this point, we can solve this like any other linear equation. So let's solve this equation for y. First, we'll get all of our y terms onto one side. Let's do that by subtracting 130y from both sides. And remember, if it's not written down, it didn't happen. And next, we can divide by the coefficient of y. And that gives us our final answer, 5127. How about a word problem? Sales tax is 8.5% of the cost of the item. If the sales tax on an item is $6.72, how much is the item? We'll let x be the cost of the item. So we know that sales tax is 8.5% of the cost. So we know the sales tax amount is $6.72. So let's replace that. And the cost of the item is x, so we'll replace that. And remember, a percentage is a fraction with a denominator of 100. So this 8.5% is really the same as 8.5 over 100. And we'll multiply that by x to get our 8.5% of x. And so our equation is 6.72 equals 8.5 over 100 times x. And now we have both fractions and decimals. Well, that's not really a problem. We know what to do with both. Since the denominator of the fraction is 100, we'll multiply both sides by 100. And that gives us, we still have a decimal. And so remember, multiplying by 10, we'll move the decimal point one place to the right. And since 8.5 has one digit after the decimal point, we want to move the decimal place one place to the right so we can multiply by 10. So multiplying both sides by 10 gives us. And finally, we can solve for x by dividing by the coefficient 85. Now the mathematical answer 67.20 divided by 85 is a perfectly good mathematical answer, but the question itself was asking about the cost of an item. And remember, you should answer questions in the same language they were asked. And in this case, we had a price amount in terms of dollars and cents, and so we should give an answer in terms of dollars and cents. So let's go ahead and compute the 67.20 divided by 85, and so we get approximately 79.06, and we want to translate this into a final answer and say something like, the cost of the item was $79.06.