X(x-1)=42 (x+7)x=18 (x-9)x=36

Question

X(x-1)=42 (x+7)x=18 (x-9)x=36

Answer 1

1.x(x+3)=10
х^2 + 3х - 10=0

Д=9+40=49

х1=-2, х2=-5

2. x(x-1)=42
х^2-х- 42=0
Д=169
х1=6, х2=-7

3.(x+7)x=18
х^2+7х-18=0
Д=121
х1=2, х2=-9

4.(x-9)x=36
х^2-9х-36=0
Д=225
х1=12, х2=-3