Simplify (31/2 ÷ 51/4) X 3: A Math Guide

by Andrew McMorgan 41 views

Hey guys! Today we're diving into a fun little math problem that might look a bit intimidating at first glance, but trust me, it's totally manageable once you break it down. We're going to tackle how to solve (312÷514)×3(\frac{31}{2} \div \frac{51}{4}) \times 3. This kind of problem tests your understanding of fraction operations, specifically division and multiplication. So, grab your calculators (or your trusty pencils!) and let's get this math party started!

Understanding Fraction Division

Alright, first things first, let's talk about dividing fractions. This is where a lot of people get tripped up, but there's a super simple trick to remember. When you divide fractions, you actually multiply by the reciprocal of the second fraction. What's a reciprocal, you ask? It's basically just flipping the fraction upside down. So, if you have a fraction ab\frac{a}{b}, its reciprocal is ba\frac{b}{a}. The rule is often remembered as "Keep, Change, Flip." You keep the first fraction, change the division sign to a multiplication sign, and flip the second fraction.

In our problem, we have 312÷514\frac{31}{2} \div \frac{51}{4}. So, following the "Keep, Change, Flip" rule, this becomes 312×451\frac{31}{2} \times \frac{4}{51}. See? We kept 312\frac{31}{2}, changed the ÷\div to a ×\times, and flipped 514\frac{51}{4} to 451\frac{4}{51}. This step is crucial because dividing by a fraction is the same as multiplying by its inverse. It might seem counterintuitive, but it's how fraction division works! Think about it this way: If you have 10 cookies and you want to divide them into groups of 2, you get 5 groups. If you wanted to divide 10 cookies into groups of 1/2 a cookie, you'd get way more groups, right? So, dividing by a smaller number (or a fraction less than 1) actually results in a larger number, which is why we switch to multiplication. This concept is fundamental in algebra and beyond, so really internalizing this step will save you a lot of headaches later on.

We're not going to multiply just yet, though. We're going to simplify first if we can. Simplifying fractions before multiplying helps keep the numbers smaller and makes the final calculation much easier. To simplify, we look for common factors between the numerators and the denominators. In our expression 312×451\frac{31}{2} \times \frac{4}{51}, we can see that the numerator '4' and the denominator '2' share a common factor of 2. We can divide both '4' and '2' by 2. So, '4' becomes '2' and '2' becomes '1'. Our expression now looks like 311×251\frac{31}{1} \times \frac{2}{51}. This simplification is a game-changer, guys. It reduces the potential for arithmetic errors significantly and is a technique you'll use constantly in higher-level math. Always look for opportunities to simplify before you multiply or add/subtract, and you'll find math becomes a lot less daunting.

Multiplying Fractions and Final Calculation

Now that we've got our division handled and simplified, it's time to multiply. Multiplying fractions is straightforward: you multiply the numerators together and the denominators together. So, in our simplified expression 311×251\frac{31}{1} \times \frac{2}{51}, we multiply 31 by 2 for the new numerator, and 1 by 51 for the new denominator. This gives us 31×21×51=6251\frac{31 \times 2}{1 \times 51} = \frac{62}{51}.

So, the result of the division part, (312÷514)(\frac{31}{2} \div \frac{51}{4}), is 6251\frac{62}{51}. But wait, we're not done yet! The original problem was (312÷514)×3(\frac{31}{2} \div \frac{51}{4}) \times 3. We've just calculated the part in the parentheses, and now we need to multiply our result by 3. So, we have 6251×3\frac{62}{51} \times 3. Remember, when you multiply a fraction by a whole number, you can think of the whole number as a fraction with a denominator of 1. So, 3 can be written as 31\frac{3}{1}. Our expression becomes 6251×31\frac{62}{51} \times \frac{3}{1}.

Again, before we multiply, let's see if we can simplify. We look for common factors between the numerators and denominators. We have '62' and '3' in the numerators, and '51' and '1' in the denominators. Notice that 51 is divisible by 3 (5 + 1 = 6, and 6 is divisible by 3, so 51 is divisible by 3). 51÷3=1751 \div 3 = 17. So, we can divide the numerator '3' by 3 (which becomes 1) and the denominator '51' by 3 (which becomes 17). Our expression now is 6217×11\frac{62}{17} \times \frac{1}{1}.

Now, we multiply the numerators and the denominators: 62×1=6262 \times 1 = 62 and 17×1=1717 \times 1 = 17. So, the final answer is 6217\frac{62}{17}. It's important to always try and simplify as much as possible because it prevents large numbers and makes the final answer easier to work with. This simplified fraction, 6217\frac{62}{17}, is our final answer. It's an improper fraction because the numerator is larger than the denominator, but that's perfectly fine in mathematics unless specifically asked to convert it to a mixed number.

Putting It All Together: Step-by-Step

Let's recap the whole process to make sure it's crystal clear, guys. When faced with a problem like (312÷514)×3(\frac{31}{2} \div \frac{51}{4}) \times 3, the order of operations (PEMDAS/BODMAS) tells us to handle the parentheses first. Inside the parentheses, we have a division problem involving fractions. The key to fraction division is to multiply by the reciprocal of the divisor. So, 312÷514\frac{31}{2} \div \frac{51}{4} becomes 312×451\frac{31}{2} \times \frac{4}{51}.

Before multiplying, we simplify. We see that 2 and 4 have a common factor of 2. Dividing both by 2 gives us 311×251\frac{31}{1} \times \frac{2}{51}. Now we multiply the numerators and denominators: 31×2=6231 \times 2 = 62 and 1×51=511 \times 51 = 51. So, the result of the division is 6251\frac{62}{51}.

Next, we address the multiplication outside the parentheses: 6251×3\frac{62}{51} \times 3. We rewrite 3 as 31\frac{3}{1} to make it a fraction: 6251×31\frac{62}{51} \times \frac{3}{1}. Again, we simplify before multiplying. We notice that 51 is divisible by 3. Dividing 51 by 3 gives 17, and dividing 3 by 3 gives 1. So, the expression becomes 6217×11\frac{62}{17} \times \frac{1}{1}.

Finally, we multiply the simplified fractions: 62×1=6262 \times 1 = 62 and 17×1=1717 \times 1 = 17. The final answer is 6217\frac{62}{17}. This step-by-step approach, focusing on simplifying at each stage, is the most efficient way to solve such problems. It ensures accuracy and makes the entire process feel much less like a chore and more like a puzzle you can solve. Remember, practice makes perfect, so try working through similar problems on your own. The more you do it, the more natural these operations will become, and you'll be breezing through fraction arithmetic in no time! Keep practicing, keep questioning, and never be afraid to break down complex problems into smaller, manageable steps. You've got this!