# how to solve this math problem?

how can i solve this easiest problem in the world??

-7/5 - 13/10 ;;;; im so dumb!!!!!!!!!!!!!!

### 20 Answers

- classicgirllLv 61 decade agoFavorite Answer
Never think you are dumb, you just have not been taught the information correctly. Try looking at your textbook before coming here for help, or go to your teacher for further help.

But anyways:

-7/5 - 13/10

Make sure you make the denominator the same

multiply the first numbers numerator and denominator by 2

so you have -7/5= - 14/10

so -14/10-13/10

keep the denominator the same and solve: -14-13

-14/10-13/10- -27/10 or -2 7/10 or -2.7

Source(s): 3rd Grade Knowledge. - 1 decade ago
You want the denominators (number on the bottom of a fraction) the same.

To do this, multiply -7/5 by 2

ie

2 * (-7/5) = -14/10

Which makes it

-14/10 - 13/10

then it's just -14-13 and make the answer over 10

ie

-14 - 13 = -27 / 10

Answer -27 / 10

Source(s): Engineering Student - 1 decade ago
First, get the least common denominator. 5 and 10 are your denominators, since 5 is a multiple of 10, then 10 becomes your common denominator because you can divide 10 by 5 and the digit itself (10).

____________

10

We'll treat -7/5 as first term and -13/10 as the second term. Get the quotient from each term by dividing the greatest common denominator (10) by the denominator of both terms.

a. 10/5 = 2

b. 10/10 = 1

Multiply the first quotient with the numerator of the first term and do the same with second quotient with the numerator of the second term, include the numeric sign (positive/negative)

a. 2 * (-7)

b. 1 * (-13)

2(-7) + 1(-13)

----------------------

10

Perform operation.

-14 - 13

----------------------

10

The answer will be -27/10

- How do you think about the answers? You can sign in to vote the answer.
- MoonRoseLv 71 decade ago
-7/5 - 13/10 (convert to the least common denominator of 5 and 10, which is 10; 5 goes into 10 two times, so multiply -7/5 by 2/2)

-7/5*2/2 - 13/10

-14/10 - 13/10 (subtract numerators)

-27/10 <===ANSWER

- Anonymous1 decade ago
Multiply both to make the denominator 50,

-7/5 x 10 = -70/50

-13/10 x 5 = -65/50

-70 - 65 = -135

-135/50

then simplify

- 2Cute2B4GotLv 71 decade ago
Both must have a common demoinator, which is 10;

so rename -7/5 to -14\10 then work problem:

-14\10 - 13\10 = -27/10

Now convert to mixed number by dividing 27 by 10

you get : - 2 and 7/10 th's or 2.7

- 1 decade ago
To subtract (or add) fractions, you need to have a common denominator. That means the numbers on the bottom have to be the same. Since the first fraction (-7/5) is in 5ths, you have to convert it to 10ths. You do this by multiplying by (2/2), since (2/2) is equal to 1, and multiplying any number by 1 gives you the same number. So...

-7/5 x 2/2

=

(-7 x 2) / (5 x 2)

I'll let you figure out the rest