We will use the Descartes` rule of signs and see how many times the signs change from positive to negative and from negative to positive from one term to the next ( two consecutive terms are with different signs ).
In this case it is 4 times ( +7x13 to -12x9, -12x9 to +16x5, +6x5 to -23 x and finally -23x to +42 ).
Answer: There are 4 real zeroes.
I think the answer would be: #2 - true; false
A "micrometer" is the best unit of measurement for measuring the size of an atom.
Answer:Each and every one of us have several roles. Organisms in a community play other roles too. An organism's role within an ecosystem depends on how it earn its nutrients. Organisms collect their nutrients in very different actions, so they have different roles in an ecosystem.
Explanation:
The food chain describes who eats whom in the wild. Every living thing—from one-celled algae to giant blue whales—needs food to survive. Each food chain is a possible pathway that energy and nutrients can follow through the ecosystem.
For example, grass produces its own food from sunlight. A rabbit eats the grass. A fox eats the rabbit. When the fox dies, bacteria break down its body, returning it to the soil where it provides nutrients for plants like grass.
Of course, many different animals eat grass, and rabbits can eat other plants besides grass. Foxes, in turn, can eat many types of animals and plants. Each of these living things can be a part of multiple food chains. All of the interconnected and overlapping food chains in an ecosystem make up a food web.
Answer:
prenatal environments
Explanation:
Depending on the number of fertilized eggs and when the zygote division occurs, there are different types of twins. For example, If the zygote is formed by the union of an ovule and a sperm that after fertilization is divided to create two embryos, they are born identical twins, these babies carry the same genetic information.
