When a farmer breeds his or her best livestock, the process involved is (chose all appropriate answers.) a artificial selection b natural selection c artificial variation d directional selection e disruptive selesction

artificial selection

Explanation:

Artificial selection is done either by inbreeding or cross breeding. Inbreeding is the crossing of genetically closely related individuals and is useful for retaining desirable qualities. Hybrids are formed from artificial selection. Hybridization results when varieties of organisms with different characteristics are crossed. The resulting offspring often show characteristics which are superior to either of the parents and are said to possess hybrid vigour.

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.

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