Question

Answer 1

a, \(A=\left\{0;\dfrac{1}{2};2;-\dfrac{1}{2}\right\}\)

b, \(B=\left\{2;3;4;5\right\}\)

Answer 2

22:

a: (2x-x^2)(2x^2-3x-2)=0

=>x(2-x)(2x^2-4x+x-2)=0

=>-x(x-2)^2*(2x+1)=0

=>x=0;x=2;x=-1/2

=>A={0;2;-1/2}

b: 3<n^2<30

=>n^2 thuộc {4;9;16;25}

mà n>0

nên n thuộc {2;3;4;5}

=>B={2;3;4;5}