which arrow or arrows represent reactions that demonstrate a conservation of mass and energy? explain your answer.

All the arrows in a combined form are used to show the biogeochemical cycle or the carbon cycle.

In this cycle, carbon is cycled between the biotic and abiotic component of the biome.

In any biogeochemical cycle, mas and energy are always conserved.

Thus, all the arrows are required to demonstrate the conservation of mass and energy.

the polynomial is a perfect square trinomial of the form a^2-2ab+b^2:

option a. true

step-by-step explanation:

9x^2-12x+4

comparing with the form a^2-2ab+b^2

1.) a^2=9x^2

solving for a: square root both sides of the equation:

sqrt(a^2)=sqrt(9x^2)

a=sqrt(9) sqrt(x^2)

a=3x

2.) b^2=4

solving for b: square root both sides of the equation:

sqrt(b^2)=sqrt(4)

b=2

to be a perfet square trinomial 2ab must be equal to 12x. let's check:

2ab = 2 (3x) (2)

2ab = 12x

correct