15pts When answering the following questions, consider the system of all polynomial equations and the system of all rational equations.

Which systems are closed under subtraction? If either system is not closed under subtraction, provide a counterexample.

it will be a cylinder. with a diameter of 8 and 4 single pieces high

step-by-step explanation:

the answer would be  

a.

3: 1

step-by-step explanation:

18 units²

step-by-step explanation:

first let's find altitude bd using the distance formula

d = √((y₂ - y₁)² + (x₂ - x₁)²)

bd = √((0 - -3)² + (0 - 3)²)

bd = √18

given the placement of points a and c, we can denote that point d bisects segment ac.

we will call ac the base.

using the distance formula

ac = √((0 - 6)² + (-6 - 0)²)

ac = √72

knowing our base and our height, we can plug these into our triangle area formula

area = (b * h)/2

area = (√18 * √72) / 2

area = (√1296) / 2

area = 36 / 2

area = 18 units²