It is the tropical plants. The text asks about population which is defined as the total number of an object or an entity. In scientific researches, samples are drawn from population to explore either qualitatively or quantitatively a phenomenon. Moreover, biologists study plants as subjects in this study.
When solving the equation, you first have h- 9/5. So it would by x=(h - 9/5). But you are not done yet. you still have to divide it by R to get x. So the final equation is x=(h - 9/5) ÷ R
46 -2c
46 decreased by means 46 minus
Twice c would be c times 2
Loss
gain means you’re getting more, which is positive