Answers plz? Help me

Problem 4

Explanation:

To name a ray, you start at the endpoint and then name any other point on the ray. So this is ray AB. You would not say ray BA since that points in the complete opposite direction.

Problem 5

Explanation:

The top and bottom segments are the same length, so (2x-2)+11 and 6x-3 are equal to one another. Solving (2x-2)+11 = 6x-3 leads to x = 3

Problem 6

Explanation:

We follow the same idea as the previous problem. This time we're solving (2x-5)+(3x+1) = 11 to get x = 3; coincidentally we get the same answer, but that won't always be the case.

Problem 7

Explanation:

Add up the endpoints and divide by 2. So we'll compute (X+Y)/2 = (-22+30)/2 = 8/2 = 4.

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