Approximately what percent of the energy is transferred from one trophic level to the next?

About 10

Explanation:

On average, only about 10 percent of energy stored as biomass in a trophic level is passed from one level to the next. This is known as “the 10 percent rule” and it limits the number of trophic levels an ecosystem can support.

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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