Math problem need help?

2 1/5 - 1 3/4 to its lowest form. The answer I got is 1 1/20 but the answer on answer sheet says 9/20. can someone solve this real quick for me?


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Most Helpful Guy

  • okay ready
    2 1/5 -1 3/4 start with the whole numbers so 2-1 =1
    now we have 1 1/5 -3/4 turn the mix number into an improper fraction
    6/5 - 3/4 now find Least Common Denominator in this case it's 20 multiply it out
    24/20 - 15/20 15 from 24 = 9 so you end up with 9/20! Hope this helps

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Most Helpful Girl

What Guys Said 5

  • It is difficult to subtract fractions without converting them first. So here is what you do.

    2 1/5 - 1 3/4
    Convert to improper fractions...
    11/5 - 7/4
    Find common denominators...
    44/20 - 35/20
    Subtract numerators...
    44 - 35 = 9
    A: 9/20

    So the answer is 9 out of 20. It is important that you understand it though instead of just getting the answer. If you need help for explaining just ask.

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    • I understand how I got it now, I just got little confuse. So only in subtraction you multiply the denominator with the whole number + the numerator? And addition, multiplication, division you don't need to?

    • Improper fractions are as you said: Take a mixed number, take the denominator of the fraction part, and multiply that denominator with the whole number. Add that to the numerator.

      What I did was convert the mixed numbers (where you have the whole numbers and a fraction) and change it to an improper fraction. Generally, once you get to higher math, most numbers are improper fractions or decimals. You do the same thing as above with addition. Addition and subtraction have very similar processes.
      In the example above... 44/20 + 35/20 = 79/20.
      To convert to mixed number, divide 79/20, and the remainder becomes the numerator. So 79/20 ==> 3 19/20

      For multiplication and division, the easiest way is to convert each mixed number as an improper fraction. From then you can multiply all the problem's numerators and add them together (<-- the answer's numerator) and then you can multiply all the question's denominators and add them together (<-- the answer's denominator).

  • 7...

    I never read the question

    And i never worked anything out.

    But im just going to guess the answer is 7...

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  • 2 1/5 = 11/5 = 44/20
    1 3/4 = 7/4 = 35/20

    44/20 - 35/20 = 9/20

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  • 2 1/5 - 1 3/4 = 11/5 - 7/4
    = 44/20 - 35/20
    = 9 /20

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    • 1. Convert mixed fractions into improper fractions
      2. Take common denominator

    • Show All
    • I'm good at math once I refresh my memory from it I'm already done with it in college. But for this assessment test To get in this new college lit's required to do math. And you'd be surprise how many people in college are still struggling with it.

    • Hmmm I guess it makes sense... all that stress must be getting to them.

  • 44/20 - 35/20 = 9/20

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What Girls Said 2

  • It 9/20 you need a common denominator 5x4=20 also 3x5=15 1x4=4 2-1=1 4-15=9 and you had to borrow from the whole that was left so it turns out to be 9/20

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  • It's 9/20.

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