4х^2-1=0
4Х^2=-1
Х^2=1/4
Х=1/2
8Х^2-5Х=0
Х(8Х-5)=0
Х=0 8Х-5=0
х= 5/8
-4х^2+16х=0
х(-4х+16)=0
х=0 -4х+16=0
х=-4
вроде так
<span>(4-x)*(4-x)*(1-x)=(4-х)^2 *(1-x)=(16-8x+x)*(1-x)=16-16x-8x+8x^2+x-x^2=7x^2-23x+16
</span><span>(2-x)*(-7-x)*(-4-x)= (-14-2x+7x+x^2)*(-4-x)=(x^2+5x-14)(-4-x)=-4x^2-x^3-20x-5x^2+56+14x=-x^3-9x^2-6x+56
</span>