Question

1)x²-2x-35=0
2)x³-9=x-9x²

Answer 1

x²-2x-35=0
D=4+140=144
x1=(2+12)/2=7
x2=(2-12)/2=-5

x³-9=x-9x²
x³+9x²=x+9
x²(x+9)=x+9
x²=1
x1=1
x2=-1