1)

$1\in A$

$y\not\in A$

$y\in B$

$A\in B$

2)

$4^2-9[34-5^5:5^3]=16-9[34-5^2]=16-9[34-25]=16-9.9=16-81=-65$

3)

a, $7x-8=713$

$\to7x=713+8$

$\to7x=721$

$\to x=103$

Vậy $x=103$

b, $2248:[119-(x-6)]=24$

$\to119-x+6=\dfrac{281}{3}$

$\to125-x=\dfrac{281}{3}$

$\to x=\dfrac{94}{3}$

Vậy $x=\dfrac{94}{3}$

c, $2016-100(x+11)=2^7:2^3$

$\to2016-100(x+11)=2^4$

$\to2016-100(x+11)=16$

$\to100(x+11)=2000$

$\to x+11=20$

$\to x=9$

Vậy $x=9$.

4)

a, $-20≤x≤20$

`\to x\in{-20;-19;....19;20}`

Tổng các số nguyên $x$ là: $(-20)+(-19)+...+19+20=0$

b, $0≤x≤30$

`\to x\in{0;1;2;...;29;30}`

Tổng các số nguyên $x$ là:

$0+1+2+...+28+29+30$

$=1+2+...+28+29+30$

$=(30+1)[(30-1):1+1]:2=465$

7)

a, $x-36:18=12-15$

$→x-2=-3$

$→x=-3+2$

$→x=-1$

Vậy $x=-1$.

b, $16.4^x=4^8$

$→16.4^x=65536$

$→4^x=4096$

$→4^x=4^6$

$→x=6$

Vậy $x=6$.

c, $|x-2|+1=5$

$→|x-2|=4$

$→x-2=4$ hoặc $x-2=-4$

$→x=6$ hoặc $x=-2$

Vậy `x\in{-2;6}`.