Answer:
When solving a rational equation, start by grouping or canceling out like terms. So cancel out x on the numerator and denominator of 2+7x/x. While the equation itself results in a contradictory statement - 5=9, the first step to figuring this out would be canceling out x.
Answer:
No
Step-by-step explanation:

therefore it doesn't coenide with pythagorian theorem
Idk but you can get the answer from somebody else
21/4 is equivalent to...
4 x 5 = 20
so, 21/4 = 5 1/4
5 1/4 = 5.25
5 1/4 = 5 2/8 = 42/8
42/8 = 84/16