How do you simplify 25+12?

3 Answers
Jun 11, 2017

See a solution process below:

Explanation:

To add two fractions they must be over a common denominator, which for this problem is 10.

To put each fraction over a common denominator we must multiply each fraction by the appropriate form of 1:

25+12(22×25)+(55×12)410+510

We can now add the numerators of the two fractions over the common denominator:

410+5104+510910

Jun 11, 2017

Choose 10 as the 'common denominator', so:

(25×22)+(12×55)=410+510=910

Explanation:

You need a 'common denominator': the number at the bottom of each fraction must be the same. To get that, we can multiply a fraction by xx, where x is any number, since xx=1.

Since our denominators are 2 and 5, we need a common denominator that both of those will divide into equally. I'm going to choose 10. It's true that 20 or 100 or 1 000 000 would also work, but we usually try to use the 'least common denominator' or 'lowest common denominator' (both are abbreviated as LCD).

To get 25 to have 10 as the denominator, I will multiply it by 22, and get 410. (we've really just multiplied it by 1, since 22=1)

To get 12 to have 10 as the denominator, I will multiply it by 55, and get 510.

Now we can add the two fractions: 410+510=910.

We can't simplify that any further, so 910 is our answer.

Jun 11, 2017

Start by finding the least common multiple of 5 and 2, the denominators. Their lcm is 10. Now we have to make the denominators both 10.

2522

Since 2/2 is one, you aren't really changing the fraction. Either way, we end up with

410 as our first fraction. Now for the second one, we make its denominator 10 as well, by multiplying by 5/5. Since 5/5=1, the fraction isn't changing.

1255

The final fraction is 5/10. Now that the denominators are the same, simply add the numerators and simplify the fraction.

5+410 => 910

However, the greatest common multiple of 9 and 10 is 1, so the fraction can't be simplified and 910 is the final answer.