P=4a
4.4≤ P≤4.8
4.4≤4a≤4.8 | :4
1.1≤ a ≤1.2
√7-7/√7-1=√7(1-√7)/√7-1= -√7(√7-1)/√7-1= -√7
Y` = (х^3/7 - 2х)` = 3/7*х^(3/7-1) - 2 = 3/7*х^(-4/7) - 2 = 3 / (7*х^4/7) - 2
5000/100*8=400
400+5000=5400
5400/100*8=432
5400+432=5832
5832/100*8=466.56
5832+466.56=6298.56