1)7х^2 - 4х - 24 + х^2 = 0
8х^2 - 4х - 24 = 0
4 (2х^2 - х - 6) = 0
2х^2 - х - 6 = 0
2х^2 - х - 4 - 2 = 0
2(х^2-1) - х - 4 = 0
х^2 -1 - х - 4 = 0
х^2 - х - 5 = 0
х(х-1) - 5 = 0
х-1-5=0
х = 6
2)7 - 6х - 3 = 10
7 - 6х = 13
6х = -6
х = -1
3)6-5х=7
5х = -1
х = -0,2