#1
S=(5a+3b)/7h
S=5a/7h + 3b/7h
5a/7h = 7h(S-(3b/7h))
5a = 7hS-3b
a = (7hS-3b)/5
#2
17,35x²-347/20 = 0
347x²/20 = 347/20 | *20
347x² = 347
x² = 1
x = 1; -1
Ответ: 1; -1
#3
2,474*10^-6 [] 247,4*10^-8
2,474/100000 [] 2,474/100000000
2474/1000 [] 2474/10000000
2,474*10^-6 больше, чем 247,4*10^-8