1: A=(x^2+3x-2)(x^2+1)
Khi x=-1 thì A=(1-3-2)(1+1)=2*(-4)=-8
Khi x=1/2 thì A=(1/4+3/2-2)(1/4+1)=-1/4:5/4=-1/5
2: \(B=\left(3x^2-2x-3\right)\left(x-3\right)\)
=3x^3-9x^2-2x^2+6x-3x+9
=3x^3-11x^2+3x+9
Khi x=-1 thì B=-3-11-3+9=3-11=-8
Khi x=1/2 thì B=3*1/8-11*1/4+3*1/2+9=65/8
3: \(C=x^4-x^3-2x^3+2x^2+x-1\)
=x^4-3x^3+2x^2+x-1
Khi x=-1 thì C=1+3+2-1-1=4
Khi x=1/2 thì C=1/16-3/8+2*1/4+1/2-1=-5/16
4: \(D=\left(x^2+3x-3\right)\left(2x+1\right)\)
=2x^3+x^2+6x^2+3x-6x-3
=2x^3+7x^2-3x-3
Khi x=-1 thì D=-2+7+3-3=5
Khi x=1/2 thì D=2*1/8+7*1/4-3*1/2-3=-5/2
5: \(E=2x^5-x^6+6x^2-3x^3-2x^5+x^6+2-x\)
=-3x^3+6x^2-x+2
Khi x=-1 thì D=3+6+1+2=11
Khi x=1/2 thì D=-3/8+6*1/4-1/2+2=21/8
