Question

math help please

Answer 1

\[\frac{ 3 }{ 5 }\div \frac{ 2 }{10 }\]

Answer 2

\[\frac{ 3 }{ 4 }\div \frac{ 3 }{ 5 }\]

Answer 3

\[\frac{ 2 }{ 3 }\div \frac{ 1 }{ 4 }\]

Answer 4

To divide by a fraction, you multiply by the reciprocal. So first re-write the problem as multiplication by the reciprocal, then reduce by any common factors, and then multiply straight across the num'r and den'r.

Answer 5

I have the easiest way for you to do this.

Answer 6

Flip the 2/10 to 10/2 than multiply it straight across.

Answer 7

BAM.

Answer 8

I'll do one that is similar to yours, as an example:

\(\Large \frac{ 2 }{ 5 }\div \frac{ 7 }{15 }=\frac{ 2 }{ 5 }\times \frac{ 15 }{7 }=\frac{ 2 }{ {\cancel5}_1 }\times \frac{ \cancel{15}^3 }{7 }=\frac{ 6 }{ 7 }\)

Answer 9

so you only have to make one a reciprocal ?

Answer 10

That's just what I said.... except that you should always reduce BEFORE you multiply.

ALWAYS.

Otherwise, you just have MORE to reduce afterwards, and it's harder to do so.

Answer 11

Yes, only the 2nd one gets changed to reciprocal.

Answer 12

And that's ONLY for division.

Answer 13

okay i think i understand now

Answer 14

Great :)

Answer 15

so the first one is 3?

Answer 16

@DebbieG

Answer 17

now i am confused on the 3/4 and 3/5 one...

Answer 18

OK, what did you try to do? Tell me where your confused.

Answer 19

When you change it to multiplication by the reciprocal, what do you have? what times what?

Answer 20

\[\frac{ 3 }{ 4 }\div \frac{ 3 }{ 5 }=\frac{ 3 }{ 4 }\times \frac{ 5 }{ 3 }\]

Answer 21

just multiply the 4 and 5 ?

Answer 22

well, first you can cancel a common factor, right?

Answer 23

the 3's?

Answer 24

And the, I'm not sure what you mean by "multiply the 4 and the 5"... that worries me, lol. You don't multiply 4*5. You multiply across the num'r, and across the den'r.

RIGHT, cancel the 3's.

Answer 25

soo... if you cancel out the 3 you would be left with 4 and 5. "
Sorry I am really bad at math lol

Answer 26

ohmygosh... i just realized i wrote down the wrong thing. It's \[\frac{ 3 }{ 4 }\div \frac{ 4 }{ ? }\]

Answer 27

4/5**

Answer 28

OK - so again, you re-write as multiplication by reciprocal. Nothing will cancel this time - that's ok. Then you must multiply across num'r, and multiply across den'r.

The method is always the same, no matter what the numbers are. :)

Answer 29

so 15/16?

Answer 30

\[\Large \frac{ a }{ b }\div \frac{ c }{ d }=\frac{ a }{ b }\times \frac{ d }{ c }=\frac{ ad }{ bc }\]

Answer 31

Right!