can anyone help me tosubtract these fractions?

Question

how do u subtract

1. 7/10 - 1/5

and how would u subtractit if there was a whole number???

Answer 1

first you have to make them equivalent by multiplying 1/5 times 2/2 so it equals 2/10 now that it has the same denominator you can subtract them. 7/10-2/10=5/10 reduce to 1/2

Answer 2

Before you do anything, you have to have both fractions converted to the same denominator (the bottom part of the fraction). In this case, the common denominator would be ten because ten goes into ten once, five goes into ten twice.
If, for example, your fractions were 7/9 and 1/5, you would have to use 45 as your common denominator.
To convert the numerator (the top number) you cross multiply - that is, you multiply the first numerator by the second denominator and multiply the second denominator by the first numerator.
Are you still with me?
Going to the 7/0 and 1/5 example, you would multiply the 7 by 5 and have 35/45 as your new fraction, multiply the 1 by 9 and your second fraction is 9/45.
Now you subtract the smaller numerator from the larger.
That would give 35-9 or 26/45 as your answer.
In the question you posed, 7/10 less 2/10 is 5/10. It is customary to reduce the fraction to its lowest level and 5/10 is another way of saying 1/2
Had there been a whole number involved, you would first convert the irregular number (that's what you call a number that has a whole number and a fraction in it) into a fraction.
Let's use your original example, only make it 1 and 7/10 and you are going to subtract 1/5 from it.
There are 10 tenths in the whole number one, so you add the 10/10 to the 7/10 and get 17/10. You convert 1/5 into tenths, just as you did before, so you are now looking at:
17/10 - 2/10.
The answer is 15/10
Again, you convert it back into an irregular number - which will be 1 (10/10) which you subtract from 15 so you are left with 1 5/10 which is equal to 1 1/2.
Okay?

Answer 3

to subtract (or add) fractions, you need to have a common denominator: the number on the bottom of the fraction needs to be the same

for example 3/8 + 1/8 = (3+1)/8 = 4/8 = 1/2

now if the fractions do not have the same denominators, you must appropriately change it without changing the value of the fraction. if you multiply a number by 1 the number doesn't change, right? so that's what we do, but we use a special form of 1 to fit the situation.

in your problem the denominators are 10 and 5. note that if we multiplied 5 by 2 it would be 10 and we could proceed.
so we have the fraction 1/5 and we want to multiply the denominator by 2 so we must also multiply the numerator by 2 in order to not change the value of this fraction. so in effect, we are multiplying 1/5 by 2/2, and 2/2 = 1 so we won't be changing the value of the fraction

7/10 - (1/5)*(2/2) = 7/10 - 2/10 = (7-2)/10 = 5/10 = 1/2

if a "mixed number" (whole number with fraction) is involved, you can change it to an improper fraction: multiply the denominator by the whole number and add the numerator -- this becomes the new numerator and you keep the same denominator. for example,
2 3/7 = (2*7+3)/7 = 17/7

Answer 4

Change 1/5 into 2/10, then subtract: 7/10 - 2/10 = 5/10 or 1/2 (reduced to lowest common denominator).
If there was a whole number, reduce it to an eqivalent fraction. For example: 3 - 7/10 = 30/10 - 7/10 =23/10, which converts to 2 3/10.
For whole numbers, remember that any number over itself is equal to 1 (10/10 = 1; 20/10=2; etc.)

Answer 5

you need to first make a common denominator. The denominator is the bottom number. (Just think denominator down)You have to find a number that both denominators go into equally. In this case, 5 goes into 10 twice and 10 goes into 10 once. So the 7/10 fraction stays the same but the 1/5 fraction changes. the 5 needs to become 10 so you multiply both the denominator and the numerator (top number) by two.this gives you 2/10. so 7/10-2/10 is the problem now. Don't touch the denominator(bottom number) when you subtract. Now that you have this common denominator you just subtract the two top numbers from eachother which will give you 5/10 in this case. I hope that this wasn't too confusing.

Answer 6

Turn 1/5 into 2/10 so that you have a common denominator

1. 7/10 - 2/10

Since 7/10 is grater then 2/10, you can subtract without borrowing from the one.

7/10 - 2/10 = 5/10 = 1/2

The 1 is left so you can just bring it down. Or you can pretend it's 0. 1/5

The answer is 1. 1/2

If instead there was 1. 1/10, then you would borrow from the one, making the fraction 11/10. [an improper fraction]

Answer 7

You'll do both the same way - find the least common denominator. (With the whole number, the denominator will be 1.)

In this case, the LCD of 10 and 5 is 10, so:

7/10 - 1/5 = 7/10 - 2/10 = (7 - 2)/10 = 5/10 = 1/2

If you need help getting the LCD, post another question. I'll answer it there, but I don't really want to put all of that here if you don't need it.

Answer 8

allright, you need to make your denominators the same....the easiest way to do this is to make the second fraction x/10. so we get:

7/10-[(1*2)/(5*2)] which becomes 7/10-2/10

Now you can look at this like (7-2)/10 which becomes 5/10

Lastly, you need to simplify

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If there was a whole number? you just need to make it into a fraction...so say you had

7/10 - 3....3 is the same thing as 3/1 so you need to multiply your numerator and denominator by 10:

7/10 - [(3*10)/(1*10)] which becomes 7/10-30/10 which becomes -23/10.

Most instructors prefer this to be put into a mixed numeral, so it would be:

-2 3/10

Answer 9

1/2
7/10 - 2/10 = 5/10 = 1/2

Answer 10

1/2

7/10-1/5 (2/10) =5/10 =1/2

Find the common denominator and then subtract.