Пошаговое объяснение:
7.
8/(х²-8) = 1,
8/(х²-8) = (х²-8)/(х²-8),
8 = х² - 8,
х² = 8 + 8,
х² = 16,
х = √16,
х1 = -4, х² = 4,
8.
22х/(х²-23) = 1,
22х/(х²-23) = (х²-23)/(х²-23),
22х = х² - 23,
х² - 22х - 23 = 0,
Д = (-22)² - 4*1*(-23) = 484 + 92 = 576,
х1 = (22 + 24)/2 = 46/2 = 23,
х2 = (22 - 24)/2 = -2/2 = -1,
9.
(х-1)/(3х+5) = (х-1)/(2х+1),
(х-1)(2х+1)/(3х+5)(2х+1) = (х-1)(3х+5)/(3х+5)(2х+1) ,
(х-1)(2х+1) = (х-1)(3х+5),
2х² + х - 2х - 1 = 3х² + 5х - 3х - 5,
2х² + х - 2х - 1 - 3х² - 5х + 3х + 5 = 0,
-х² - 3х + 4 = 0,
х² + 3х - 4 = 0,
Д = 3² - 4*1*(-4) = 9 + 16 = 25,
х1 = (-3 + 5) / 2*1 = 2/2 = 1,
х2 = (-3 - 5) / 2*1 = -8/2 = -4