Can you solve this? -2/3 + -4/5?

Question

And show me how?

Answer 1

-2/3
+
-4/5
=

(Here’s an easy way to remember which is which)
Notre Numerator
Dame Denominator
You can not add or subtract 2/3 from 4/5 because the denominators are not in common with each other right now. You need to find a the first number that both Denominators have in common. In this case, it’s 15. So now your problem looks like:

-10/15 (another way of saying two-thirds)
+
-12/15 (another way of saying four-fifths)
=

So now, what is –10 + -12?
-22

Add the denominator, and that is:
-22 /15

THIS IS CALLED A TOP HEAVY FRACTION. It’s top heavy because the number on top is higher than the one on bottom.

If you’re teacher wants a mixed number, follow the next steps.

How many times does 15 go into 22? The answer is: 1.
That 1 becomes a whole number. It is no longer a fraction.
How much of is left over? You put 15 into 22, so you took 15 away from 22. You have 7 left over. That 7 becomes part of the fraction.
Your final answer will look like this:
-1 7/15

Answer 2

Just as you can't add 1/3 and 1/5 as is, you can't subtract fractions with different denominators without changing them.

One way is to change them both to decimals and then they can be added and subtracted like any numbers. However, -2/3 is a repeating decimal, so you will get a tricky answer.

The simplest way is to convert both of these to a common denominator. Think of it like a pizza problem. You've got two whole pizzas. One is cut into 3 big pieces. The other is cut into 5 big pieces.

Now suppose a greedy friend of yours eats two of the three slices from one pizza and four of the five slices from the other pizza. You want them to pay for their share of it (which is most of the whole thing) but you do want to be fair about it. If the two pizzas together cost $30, how much should they pay?

You know it's way more than half, right? And you not it's not quite the whole thing, so it's somewhere between $15 and $30 and a lot closer to $30.

Now, there are a lot of ways to figure this out but suppose you decide to do it by (before they actually take their slices) trying to have each pizza cut into the same number of slices. Well, the first one is already in three and it would be really complicated to cut it in a way that would make five. And since the other is already in five, it's impossible to rearrange it to make three pieces.

Do you see how if you cut each of the three pieces into fives, you will have 15 pieces and if you cut each of the five pieces into three you will have 15 pieces? So now your friend takes 10 of the little pieces in the first pizza and 12 of the little pieces in the second. That's 22 pieces out of a total of 30.

So 22 pieces out of 30 pieces means $22 out of $30.

In math terms you decided on a common denominator of 15 and converted 2/3 into 10/15 and 4/5 into 12/15. Since each was negative, you end up with negative 22/15 or negative 1 and 7/15.

Hope that helps.

Jay Cutts
http://www.advising-help.org

Answer 3

Okay, first, convert your denominator so that it's common - multiply 2/3 by 5, and multiply 4/5 by 3.

Now, your equation is -10/15 + -12/15.

When you have "plus negative" (you're adding a negative number), it's the same thing as saying -10/15 - 12/15. So subtract, and you get -22/15.

Okay, now reduce your fraction so that it's proper - how many times does 15 go into 22? Once, so that's your whole number, and the leftover is your fraction.
So your answer is -1 7/15, or negative one and seven fifteenths.

I hope that helps.

Answer 4

-2/3 = -10/15
-4/5 = -12/15

-2/3 + -4/5 = -22/15 =

Answer 5

in order to add or subtract fractions, you need to make the denominators the same by finding the least common denominator.

If you look at the denominators, what would be the smallest factor of those two numbers?

When you figure that out, you need to multiply the numerator by whatever amount you multiplied the denominator so that the fraction is still the same.

Once you have fractions where the denominators are the same, you simply do the equation ... a negative number plus a negative number is going to be a negative number

I'm not going to tell you what the LCD is or what the answer is -- you need to try to take this step by step

Answer 6

common denominator first
-2/3=- 10/15
- 4/5=-12/15
-10/15-12/15=-22/15=-1 7/15

Answer 7

yes, i can solve that.




and if you wanted the answer too, it was.......
-2/3 = -10/15 by multiplying by 1 (5/5) on both sides
then mult. -4/5 by 3/3 to get -12/15
-10/15+ (-12)/15 = -22/15 or -1 and 7/15

Answer 8

-2/3 + -4/5 = -(2*5) / (3*5) + -(4*3) / (5*3) ----> to get same denominator
-10/15 + -12/15 = -10 + -12 / 15
-22/15

Answer 9

-2/3 + -4/5 is the same as
-10/15 + -12/15
then you add -10 and -12 to get -22
you keep 15 as your denominator and get your answer

-22/15 or as a mixed number -1 7/15


hope this helps!

Answer 10

The common denominator is 15.

-10/15 +-12/15= -22/15 +- = -

Check it out.