Question

need help pic inserted

Answer 1

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

Answer 2

um huh

Answer 3

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

Answer 4

fun fact:

\[\frac{ x^2 -1 }{ x-1 } = \frac{ (x+1)(x-1) }{ x-1 } = \frac{ x+1 }{ 1 }\]