X2-11x-42=0 -2x^2-15x-2=0 x^4-13x^2+36=0

1)2х-11х-42=0
2х-11х=0+42
-9х=42
х=42:(-9)
х=42/-9
х=14/-3
2)-2х•2-15х-2=0
-2х-15х=0:2+2
-17х=2
х=2 : (-17)
х=2/-17
3)х•4-13х•2+36=0
4х-13х=0:2-36
-9х=-36
х=36:9
х=4