b)(3+√2)(9-3√2+2)=
27-9√2+6+9√2-3·2+2√2=
27+2√2
c)(x-2)(x²+2x+4)=x³+2x²+4x-2x²-4x-8=
x³-8
d)(x²+x+1)(x-1)=x³-x²+x²-x+x-1=x³-1
e)(1-x+x²)(x+1)=x+1-x²-x+x³+x²=x³+1
f)(4x+1)(16x²-4x+1)=64x³-16x²+4x+16x²-4x+1=64x³+1
g)(x²-2x+4)(x+2)=x³+2x²-2x²-4x+4x+8=x³+8
h)(3+x)(9-3x+x²)=27-9x+3x²+9x-3x²+x³=x³+27