Question

the help video did not help what do i put in the blank boxes u get a lot of points from this also plz actually anwser don't put "idk" (yes that has happened)

Answer 1

Basically, this is trying to say that

`a(b+c)=ab+ac`.

15 can be split up into 10 and 5.

And multiplying 3 by 15 is the same as the sum of multiplying 3 by 10 and 3 by 5.

`3*10=30` (First Box)

`3*5=15` (Second Box)

---------------------

`30+15=45`

`3*15=45`

(Proof that it works)