how do you add a negetive and a positive faction? -5/8 + 2/9 = ?

First you need to find the equivalent fractions with a common denominator.

Then you subtract the negative number from the positive number.

I'll be glad to check your answer.

I came out with a common denominator of 72.

do I just put -5/72 + 2/72 = -3/72? I haven't done Algeria in 50 years. I am very rusty.

You're on the right track.

But -- you need to multiply the numerator by the multiple of the denominator to get the equivalent fraction.

72 divided by 8 = 9
9 times 5 = 45

-5/8 = -45/72
2/9 = 16/72

16/72 - 45/72 = -29/72

Thank you Sue! My daughter says she thinks she has it now. I hope she does, because I am till confused. You know its true what they say, It's hard to teach an old dog new tricks. Thanks again, Dean

You're very welcome.

I understand you. But hang in there. I'm 76 and am still learning.

To add fractions with different signs (positive and negative), you need to follow these steps:

Step 1: Find a common denominator for the fractions.
To add -5/8 and 2/9, you need to find a common denominator, which is the least common multiple (LCM) of 8 and 9.

The multiples of 8 are: 8, 16, 24, 32, 40, 48...
The multiples of 9 are: 9, 18, 27, 36, 45, 54...

The LCM of 8 and 9 is 72.

Step 2: Convert the fractions to have the same denominator.
To do this, multiply the numerator and denominator of each fraction by the appropriate factor that will make the denominator equal to 72.

For -5/8:
(-5/8) x (9/9) = -45/72

For 2/9:
(2/9) x (8/8) = 16/72

Now both fractions have a denominator of 72.

Step 3: Add the fractions together.
You can now add the fractions by adding their numerators while keeping the common denominator.

-45/72 + 16/72 = (-45 + 16)/72 = -29/72

So -5/8 + 2/9 = -29/72.

Thus, the answer is -29/72.