The answer to this is B. anthracite coal. Organic matter gradually turns into coal over many years of high pressure and temperature under the earth. The lowest form of coal is peat (where it is still recognizably plant matter), followed by lignite, then sub-bituminous coal, then bituminous coal, then anthracite. These are also ordered from lowest to highest composition of carbon.
3/4 times 1/5 = 3/20
4/7 times 5/12 = 5/21
3/8 times 2/9 = 1/12
4/5 times 5/8 = 1/2
Operations with variables can give you excluded values by making the denominator equal to zero.
Ex. 48/60 always equals to 4/5 but 4x/6x is not always equal to 2/3 because when you make x equal to zero it makes the equation invalid.
Answer:
The solution of the inequation 
is ![\left(-\infty,-\frac{2}{3}\right]\cup\left[\frac{5}{2},+\infty\right)](https://tex.z-dn.net/?f=%5Cleft%28-%5Cinfty%2C-%5Cfrac%7B2%7D%7B3%7D%5Cright%5D%5Ccup%5Cleft%5B%5Cfrac%7B5%7D%7B2%7D%2C%2B%5Cinfty%5Cright%29)
.
Step-by-step explanation:
First of all, let simplify and factorize the resulting polynomial:
Roots are found by Quadratic Formula:
![r_{1,2} = \frac{\left[-\left(-\frac{11}{6}\right)\pm \sqrt{\left(-\frac{11}{6} \right)^{2}-4\cdot (1)\cdot \left(-\frac{10}{6} \right)} \right]}{2\cdot (1)}](https://tex.z-dn.net/?f=r_%7B1%2C2%7D%20%3D%20%5Cfrac%7B%5Cleft%5B-%5Cleft%28-%5Cfrac%7B11%7D%7B6%7D%5Cright%29%5Cpm%20%5Csqrt%7B%5Cleft%28-%5Cfrac%7B11%7D%7B6%7D%20%5Cright%29%5E%7B2%7D-4%5Ccdot%20%281%29%5Ccdot%20%5Cleft%28-%5Cfrac%7B10%7D%7B6%7D%20%5Cright%29%7D%20%5Cright%5D%7D%7B2%5Ccdot%20%281%29%7D)
and 
Then, the factorized form of the inequation is:
By Real Algebra, there are two condition that fulfill the inequation:
a) 
b) 
The solution of the inequation is .
