B=book
a=backpack
b=50
b=2a-20
50=2a-20
2a=75
a=37.5
it cost $37.5
La Biología Viene Siendo Una Ciencia Que Estudia El Origen De La Vida Si Evolucion Sus Propiedades Y Sud Cuidados También Describe las Características Y Comportamiento De Las Especies De Todo El Mundo
El turismo Biologico :Es Una Propuesta para El Viajero Interesado por Conocer Los Componentes Naturales De Algún Lugar Como La Fauna Y La Flora
Nitrogen-fixing bacteria convert nitrogen gas from air into a form that plants can use to make proteins. Free-living nitrogen-fixing bacteria are also found in the soil. When they die the nitrogen they have fixed into their biomass is converted into ammonium .
Chicken breast-protein
Banana-carbohydrate
(Sorry if I’m wrong about the banana, most of my sources said carbohydrates)
Explanation:
producers? O A. Producers and primary consumers compete with each other for food sources. B. Primary consumers eat secondary consumers, which rely on producers for food. C. Producers provide primary consumers with the chemical energy they need. D. Primary consumers provide producers with the chemical energy