2x³-7x²=0
x²(2x-7)=0
x²=0 ==> x=0
2x-7=0 ==>2x=7 ==> x=7/2
-3x³+8x²+x=0
x(-3x²+8x+1)=0
x=0
-3x²+8x+1=0
Δ=8²-4*(-3)=64+12=76=4*19
√Δ=2√19
x₁=(-8-2√19)/(-6)=-2*(4+√19)/(-2)*3=(4+√19)/3
x₂=(-8+2√19)/(-6)=-2*(4-√19)/(-2)*3=(4-√19)/3
x³+x²-2x-2=0
x²(x+1)-2(x+1)=0
(x²-2)*(x+1)=0
x+1=0 ==> x=-1
x²-2=0 ==> x²=2 ==>x=√2 i x=-√2
