B How do you multiply fractions again? My brain just froze 😅

[goodcomfort]

I was helping my younger sibling with homework and totally blanked—how exactly do you multiply fractions again? I feel like I knew this once upon a time but it's just… gone.

 

[fresh_42]

$\dfrac{a}{b}\cdot \dfrac{c}{d}=\dfrac{a\cdot c}{b\cdot d}.$

 

[fresh_42]

For the record:

$\dfrac{a}{b} \, : \,\dfrac{c}{d}=\dfrac{a\cdot d}{b\cdot c}$

$\dfrac{a}{b}+ \dfrac{c}{d}=\dfrac{a\cdot d+b\cdot c}{b\cdot d}$

$\dfrac{a}{b}- \dfrac{c}{d}=\dfrac{a\cdot d-b\cdot c}{b\cdot d}$