Please answer the question in the picture

Organisms that live in the alpine and taiga biomes have developed unique adaptations that aid in their survival. the douglas-fir is a conifer tree that grows in the taiga biome. it has an average height of about 70 feet, and its wood is an important source of lumber.

What does x = in this equation x+3+2x=x+5

The number of fish in a lake can be modeled by the exponential regression equation y=14.08 x 2.08^x where x represents the year