How do you solve this equation step-by-step? (below)

4a + 8 - 2a - 3 = 45

Step-by-step explanation:

4a-2a+8-3=45

2a+5=45

2a+5-5=45-5

2a/2=40/2

a=20

0.85 or 85%

step-by-step explanation:

1) divide 23 by 27

2) round the decimal to the nearest 10

3) so your answer would be 0.85 or 85%

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