simplyfing an an addition of two fractions

eddy2017

eddy2017

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I am not understanding a simplification made by a teacher of this equation
$(4/3+4/5)*15/4 he cancels all 4's and is left with (1/3 +1/4)*15 = 8/15 * 15

where dies the 8 comes from?. I am not seeing that.
thanks for any help,
eddy
 
eddy2017 said:
I am not understanding a simplification made by a teacher of this equation
$(4/3+4/5)*15/4 he cancels all 4's and is left with (1/3 +1/4)*15 = 8/15 * 15

where dies the 8 comes from?. I am not seeing that.
thanks for any help,
eddy
Click to expand...
How would you simplify:

(4/3 + 4/5) * 15/4

Please show your work (step by step)
 
Subhotosh Khan said:
How would you simplify:

(4/3 + 4/5) * 15/4

Please show your work (step by step)
Click to expand...
oh, yes, sorry about that

this is the original equation
2(5/3 - 1) + 2 (7/5 - 1) / (5/3 -7/5)

(2 * 2/3) + 2 * 2/5) / 4/15 --------------------I multiply by the multiplicative inverse to get rid of the fractional form

(2 * 2/3) + 2 * 2/5) / 15/4

(4/3+ 4/5) * 15/4 ------------ the teacher cancels out all 4's replacing the 4's in the numerator of the fractions with 1
and the goes on to set this fraction up

8/15 * 15 --------------- both 15's cancel out and we're left with 8

I did not know how he got the 8?????. I'm confused there. the rest of the ops I understand perfectly well
 
(4/3+4/5)*15/4 he cancels all 4's and is left with (1/3 +1/4)*15
The bold 4 should be a 5.
 
eddy2017 said:
(2*2/3 + 2 * 2/5) / 15/4
Click to expand...
Eddy, remember what I said about parenthesis in the other post. You repeated the same mistake

what to do to get rid of a fraction in the denominator?

&& Hi, I was wondering if what i have done here is correct 2(5/3 - 1) + 2(7/5-1) / 5/3 -7/52(2/3) + 2(2/5)/ 4/15 my question is , can I do this to get trid of the 4/15 i nthe denominator, that is, multiply the numerator by the multiplicative inverse of the fraction in the denominator? 2(2/3) +...
www.freemathhelp.com
 
eddy2017 said:
oh, yes, sorry about that

this is the original equation
2(5/3 - 1) + 2 (7/5 - 1) / (5/3 -7/5)

(2 * 2/3) + 2 * 2/5) / 4/15 --------------------I multiply by the multiplicative inverse to get rid of the fractional form

(2 * 2/3) + 2 * 2/5) / 15/4

(4/3+ 4/5) * 15/4 ------------ the teacher cancels out all 4's replacing the 4's in the numerator of the fractions with 1
and the goes on to set this fraction up

8/15 * 15 --------------- both 15's cancel out and we're left with 8

I did not know how he got the 8?????. I'm confused there. the rest of the ops I understand perfectly well
Click to expand...
(2 * 2/3) + 2 * 2/5) / 4/15 --------------------I multiply by the multiplicative inverse to get rid of the fractional form (2 * 2/3) + 2 * 2/5) / 15/4

Nope, you did not multiply by 15/4, as clear as can be you divided by 15/4.
 
the result of the operation in the denominator is 4/15
then i multiply the numerator by the inverse of 4/15 which is 15/4.
Is this incorrect?
 
can i post the video. I will give you the exact time and everything. Well, i think videos are not showing when pasted. not even the link. the links gets swallowed by the screen which is not showing anything.
 
eddy2017 said:
the result of the operation in the denominator is 4/15
then i multiply the numerator by the inverse of 4/15 which is 15/4.
Is this incorrect?
Click to expand...
It is incorrect when you write /(15/4) when you say that you are multiplying by 15/4 which is written as *(15/4).

Yes, you did not use parenthesis but I am not concerned with this right now. You clearly wrote /15/4 which means that you are dividing by 15/4
 
this was when checking some problems about age online and some tricks and happened upon this video. on the second problem the teacher does that calculation towards then of the second problem and I can't understand what he did. I didn't get that part. Did not get his English there either.
timer 10:17

 
Jomo said:
Clearly says that This video is unavailable
Click to expand...
it is on youtubeun der this subtitle:

Two SHORT TRICKS to CRACK AGE PROBLEMS
Suresh Aggarwal​

.when I copy the link and paste it, the link does not show. it shows like unavailable. there must be a glitch on the forum page.
 
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