1.
x=7,13 +-0,04
x min = 7,13-0,04 = 7,09
x max = 7,13+0,04 = 7,17
x∈[7,09; 7,17]
2.
y = (x max + x min) / 2 = (5,782 + 4,138) / 2 = 4,96
a = x max - y = y - x min = 5,782 - 4,96 = 0,822
25^x - 120*5^x - 625=0
заменим 5^x = t
t^2 - 120t -625=0
D= 14400+2500=16900=130^2
t= 125; t= -5
1)5^x=5^3
x=3
2)5^x= -5 - net recheniya