Question

Substraction of rational numbers is associative.
If true then enter $1$ and if false then enter $0$

Answer 1

False
$a-(b-c)\ne (a-b)-c$
$\frac{1}{2}-(\frac{2}{5}-\frac{3}{4})\ne (\frac{1}{2}-\frac{2}{5})-\frac{3}{4}$