You can probably find algae that conduct photosynthesis
in polar regions or hot springs
on your dinner plate
all of the above

✿   this landform has a high elevation and a high relief

✿   this landform is a mountain

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.

: -)