Need help ASAP giving 30 points and a branleist

That rock I believe is Mica

Biotite mica Biotite mica can be easily identified by its dark brown to black color that is a result of the high ferro-magnesium content of the mineral. It is a common rock forming mineral that is found in granite, syenite and other igneous rocks. It is also found in metamorphic rocks such as gneisses and schists

Step-by-step explanation:

As a naturally-forming silicate mineral, mica occurs in igneous rock, which consists of layers of volcanic material. At this stage, mica is crystal in form and is mined to extract it.  The richest natural sources of mica are coarsely grained igneous rocks known as pegmatites

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this

1. minimum

2. 6400

3. eight

hope this !