a) \(A=x\left(2x+1\right)-x^2\left(x+2\right)+x^3-x+3\)
\(=2x^2+x-x^3-2x^2+x^3-x+3=3\)
b) \(B=x\left(2x^2-4x+8\right)+12x^2\left(\dfrac{1}{3}-\dfrac{1}{6}x\right)-8x+9\)
\(=2x^3-4x^2+8x+4x^2-2x^3-8x+9=9\)
c) \(C=t\left(2t^3+t+2\right)-2t^2\left(t^2+1\right)+t^2-2t+1\)
\(=2t^4+t^2+2t-2t^4-2t^2+t^2-2t+1=1\)
d) \(D=4x\left(3x+2\right)-6x\left(2x+5\right)+22x-21\)
\(=12x^2+8x-12x^2-30x+22x-21=-21\)
a) A=x(2x+1)-x^2(x+2)+x^3-x+3
A=2x^2+x-x^3-2x^2+x^3+3
A=x+3
b)B =x(2x^2-4x+8)+12x^2(1/3-1/6x)-8x+9
B =2x^3-4x^2+8x+4x^2-2x^3-8x+9
B=9
c) C=t(2t^3+t+2)-2t^2(t^2+1)+t^2-2t+1
C=2t^4+t^2+2t-2t^4-2t^2+t^2-2t+1
C=1
d) D= 4x(3x+2)-6x(2x+5)+22x-21
D = 12x^2+8x-12x^2-30x+22x-21
D=-21
