Please help! This really doesn't make sense to me. I NEED HELP

Find the scale of the two similar sides with known dimensions:

45/27 = 1 2/3

Figure A is 1 2/3 times larger than B. Now multiply the similar side of B to find x:

x = 18 x 1 2/3

x = 30

x = 30

30

Step-by-step explanation:

(This is a similarity question)

So,

X/18 = 45/27

Then cross multiplication

X= 45×18/ 27

X= 30

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