What did they do with the fractions?

[rose dome]

in the 4th step, how did they make the fractions like that ?
here is the answer source -
https://byjus.com/question-answer/if-abc-1-show-that-frac-1-1-a-b-1-frac-1-1-b/

[gritty pagoda]

1. Wait patiently for a helper to come along.
2. Once someone helps you, say thank you and close the thread with:

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3. Feel free to nominate the person for helper of the week in #helper-nominations

[tough glade]

Which one

The 1/(b+ab+1)/b

[rose dome]

this part specifically

I do understand the second term, just the 1st and 3rd ones are puzzling

[tough glade]

Well for first it looks like they multiplied by b/b

[rose dome]

what about the third one?? how did the denominator become ab+1+b

[tough glade]

They multiplied everything by ab/ab

[rose dome]

https://witeboard.com/f4370880-13c0-11ee-9a5e-a12f0b96947f
this is a sharable witeboard. kindly do join and show me

[tough glade]

Ok

Do you want 1st and 3rd or just third

[rose dome]

1 and 3

[tough glade]

do you see

[rose dome]

yes

Thanks soo much I have a test today

[tough glade]

good luck

[rose dome]

Thanks

+close