so solving i get: $$ dx+c+d = a$$
$$dx+d=a-c$$
$$dx+d=c$$
$$dx=c-d$$
$$\frac{dx}{d} = \frac{c-d}{d}$$ $$x=c$$
Check: $d \cdot c + c +d = a$
$b +c+d =a$
$d+d = a$ so it works :)
iv only just started learning finite sets in discrete math and im having trouble with it so can someone please let me know if this is correct, i think it is but i just want some clarification.
-thanks
To ensure that you get full marks, I'd suggest writing what the identity under each operation is, and being clear about what the additive inverse is, when you make use of it. You are indeed correct.