If 2a+3b=12 and 3b-4=2, then what is the value of a?

The graph shows a trend in an ecosystem over time caused by increased pollution in the region. what can you conclude from the graph? a. there’s lower biodiversity among birds. b. there’s a higher reproductive rate among birds. c. there’s a significant decline in the number of producers. d. other types of animals were unaffected by pollution.

How are 3-d printers useful in studying evolution? a. to color the fossils of organisms b. to create clones of extinct organisms c. to create replicas of fossils d. to prepare paper cutouts of organisms e. to study the composition of fossils

Jerrold has to buy 12 copies of a textbook which costs $36.25 per copy. how much must he spend for them?