What term defines kind of species that have been introduced to an ecosystem by man?

Answer;

-Exotic species

Explanation;

-An exotic species or an introduced species ( or alien species, non-indigenous species, or non-native species) is a species living outside its native distributional range, which has arrived there by human activity, either deliberate or accidental.

-The major distinguishing feature between exotic and invasive species is that exotic species is harmless to the ecosystem whereas invasive species is harmful to the ecosystem.

-For example important introduced pest species which include chestnut blight, Dutch elm disease, etc. and plant species such as honeysuckle, buckthorn, etc.

multiplying and dividing the two decimals and the eqations by the same number of the overalls

well, i believe that the answer is 2. : 3