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How to solve the following: 4a/15 = 3/5  

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rupalrox | Student, Undergraduate | eNotes Newbie

Posted February 26, 2010 at 6:58 PM via web

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How to solve the following:

4a/15 = 3/5

 

11 Answers | Add Yours

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krishna-agrawala | College Teacher | Valedictorian

Posted February 26, 2010 at 7:40 PM (Answer #1)

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We need to solve the equation "4a/15 = 3/5"

This equation can be rewritten as:

a*(4/15) = 3/5

To make the left hand side of the equation equal to a we multiply bot side of equation by 15/4. Giving

a*(4/15)*(15/4) = (3/5)*(15/4)

We simplify this equation in following steps.

a*(4*15)/(15*4) = (3*15)/5*4)

a*(60/60) = 45/20

a = 9/4 = 2.25

 

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neela | High School Teacher | Valedictorian

Posted February 26, 2010 at 7:14 PM (Answer #2)

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To solve 4a/15 = 3/5.

Solution:

4a/15 =3/5. Multiply by 15 both sides :

15*4a/15= 3*15/5 Or

4a = 9. Divide by 4 both sides:

a = 9/4 = 2.25

 

 

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amitparmar | Student, Undergraduate | eNoter

Posted February 27, 2010 at 5:06 AM (Answer #3)

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given that,

4a/15=3/5

we may written as

4a=3*15/5

or,4a=3*3

or,4a=9

or,a=9/4

a=2.25

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yoobie | High School Teacher | eNotes Newbie

Posted March 18, 2010 at 3:30 PM (Answer #4)

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To solve this question, the most important part is to know that 'a' is what you have to find.

In this quetion, it is easy to see what 'a' is because 15 is a multiple of 5. If you mutiply 5 by 3, you will get 15! This is what the two denominators are. So, you have to do the same thing to the numeratorl you have to multiply 3. 3x3 is 9, and that is equal to 4a.

To put it neatly, it is:

4a/15=3/5

4a/15=9/15 (At this stage, you don't have to be concerned of the denominators because they are equal)

4a=9

a=9/4

a=2+1/4

This can be said because with the demonimators equal, the numerators have to be equal as well.

So, in doing these sorts of questions, you have to make the denominators of both sides equal, and then solve the variable.

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isbeatbox | Student, Grade 11 | eNotes Newbie

Posted March 31, 2010 at 1:05 AM (Answer #5)

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This is how I would do it

4a/15=3/5

5(4a)=15(3)

20a=45

a=2.25   or  a= 2 1/4

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Wiggin42 | Student, Grade 11 | Valedictorian

Posted March 23, 2014 at 4:26 PM (Answer #6)

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4a/15 = 3/5

4a = (3/5) x 15 = 9

a = 9/4

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atyourservice | Student, Grade 10 | Valedictorian

Posted April 19, 2014 at 9:57 PM (Answer #7)

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`4a/15 = 3/5`

cross multiply

`4axx5=20a`

`15xx3=45`

`20a=45`

divide by 20

`(20a)/20 = 45/20`

a= 45/20

this can be simplified into 9/4

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zumba96 | Student, Grade 11 | Valedictorian

Posted May 14, 2014 at 11:42 PM (Answer #8)

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Cross multiply

4a/15=3/5

Once you cross multiply; 4a(5)=15(3)

20a=45

a=9/4

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acompanioninthetardis | Student, Undergraduate | Valedictorian

Posted May 20, 2014 at 2:42 AM (Answer #9)

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4a/15 = 3/5

4a=45/5

4a=9

a=9/4

a=2, 1/4.

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jess1999 | TA , Grade 9 | Valedictorian

Posted June 23, 2014 at 12:30 AM (Answer #10)

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4a/15 = 3/5

To solve this, first we should do cross multiplying ( multiply 4a with 5 and 15 with 3 )

By cross multiplying, your equation should look like

20a = 45 now divide both sides by 20

By dividing, your equation should be

a = 45/20 simplify

a = 9/4 which is your answer

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nisarg | Student, Kindergarten | Valedictorian

Posted June 25, 2014 at 12:05 AM (Answer #11)

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4a/15 = 3/5 so to get rid of the denominators multiply both sides by 15

4a=9        then divide both sides by 4

a=9/4 or a=2.25 is your answer

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