Mark jogged 3 and5/7 km. His sister jogged 2 and 4/5 km. How much farther did mark jog?

32/35 km

Step-by-step explanation: First you have to find a common denominator between these two mixed numbers. That basically means that you have to convert them so that they both have the same denominator, that way they can be compared to one another. The easiest way to do this is to just multiply the denominators. 5 x 7 = 35. I will use 35 as my denominator. Then you multiply the numerators by the same number that you multiplied the denominator by to get 35. Since 7 x 5 = 35, 5 x 5 = 25. Same with the second fraction. 5 x 7 = 35. 4 x 7 = 28. The mixed numbers we have are now 3 and 25/35 and 2 28/35. To figure out how much farther Mark jogged we just take his distance, and subtract his sister's distance from it. 3 25/35 minus 2 28/35 = 32/35.

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