another basic algebra 2 question????

Question

ok so i have these fractions again

27 1/2 - 18 5/8

ok so what do you do when the 8 and 2 aren't the same numbers?/ or does it matter

please explain

Answer 1

71/8 or you can change it to a mixed number: 8 7/8

you can find a common denominator between 1/2 and 5/8

from there (with the first mixed fraction) you multiply 27*4+4, with the 2nd mixed fraction you multiply 18*8+5.

then you subtract 220/8 - 148/8, and you get 71/8 (or change it back to a mixed number 8 7/8.

Answer 2

For this, subtract the fractions first. Since 5/8 is greater than 1/2, make the 1/2 into a 26 3/2 or 26 + 12/8.

12/8-5/8=7/8. now do 26-18, which equals 8. So...you get 8 and 7/8.

You can only add/subtract the numerators of fractions if and only if their denominators are the same. so you make sure you change their denominators to the LCD (least common denominator) before you add/subtract. Only when you are multiplying/dividing fractions would the denominator not matter.

Answer 3

ok i took algebra 2 last year so i think i still remember :-)

first turn 27 and 1/2 into an improper fraction by multiplying the 27 by 2 and adding 1.

then do the same for the other number.

then since 2 is a factor of 8, it has to be equal to 8 for the operation to work.

what times 2 is 8?

take that number and mulitply the top and bottom numbers of the fraction with the two on the bottom (denominator)

then its just simple subtraction from there.

if possible, simplify.

Answer 4

First you must convert these mixed numbers into improper fractions. You do this by multiplying the whole by the denominator and adding the numerator. This number is your new numerator (keep the same denominator). E.g. 2 1/2 = 2 * 2 + 1 / 2 = 5/2.

Once you've done this, you need to find the lowest common denominator for the two fractions. Here, you will have a 2 and an 8, so your LCD will be 2. Make both fractions have the same base of 2, and you can then finally subtract.

Answer 5

since the 8 and 2 aren't the same numbers, you have to find a common number that they both have. you can't add or subtract fractions unless they have the same denominator (bottom number) since 8 is a multiple of 2, you can just keep the denominator of 8. now, you 2 x 4 = 8... so you have to multiply the numerator (top number) by 4. this way... the fraction becomes 27 4/8. 4/8 is the same thing as 1/2 except 1/2 is the reduced version.

Answer 6

Find a common denominator (in this case 8). 27 1/2 is the same as 27 4/8. 27 4/8 - 18 5/8 = 8 7/8

Answer 7

Find the common denominator-which is 8
Multiply 1/2 by 4 to get 8, which is 4/8
Subtract 18 5/8 from 27 4/8

Answer 8

Find the lowest common denominator. It is 8, since 2 divides into 8. 1/2 is 4/8, so you have 27 4/8 - 18 5/8, which is 8 7/8.

Answer 9

okay so 2 and 8 are the denominators. they are different and in order to solve the problem, you must make them the same. the LCD of 2 and 8 is 8, so the problem now becomes 27 4/8 - 18 5/8

Answer 10

You have to convert the numbers to top heavy fractions first.
(55/2 and 149/8)

Then you get the same denominator by multiplying the first number by 4/4.
(220/8 - 149/8)

Which equals 71/8 or 8 7/8.