Pure ammonia (NH3) is an example of a(n) . element compound mixture solution

your answer is true

i am 100% sure

explanation:

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)