Simplify: (3x2 − 8xy + y2) − (7x2 − 4xy − 5y2)

Step-by-step explanation:

(3x2 − 8xy + y2) − (7x2 − 4xy − 5y2)

First, we remove the parenthesses. We can just remove the first parnthesses because there isn't any sign before them. When removing the second ones, we will change the sign of every term in it. It becomes:

Now we will combine the like terms. That means that we will subtract 7x2 from 3x2, add 4x to -8x etc.

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