a)
x³-10x²+25=x(x²-10x+25)=x(x-5)²
b)
x³-9x=x(x²-9)=x(x+3)(x-3)
c)
x^4-49=(x²+9)(x²-9)=(x²+9)(x+3)(x-3)
d)
x³-3x²-10x-x(x²-3x-10)=x(x+2)(x-5)
Δ=(-3)²-4·1·(-10)=9+40=49, √Δ=√49=7
x1=(3-7)/2
x1=-2
x2=(3+7)/2
x2=5
e)
4x^4-7x^3=x^3(4x-7)
