4 Mary and Margaret are looking at a map of a running path in a local park. Which is the shorter
path from E to F, along the two semicircles or
along the larger semicircle? If one path is shorter,
how much shorter is it?

2km

Step-by-step explanation: the half of 4km so if we divide it by 2 because there are 2 semi circles

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

-12 > a

step-by-step explanation:

-11 > 1 + a

subtract 1 from each side

-11-1 > 1-1+a

-12 > a