a/20:(x+1)=2

<->x+1=20:2=10

<->x=10-1=9

b/3^8x+4=81^3

,<->3^8x+4=(3^4)^3=3^12

->8x+4=12->8x=8->x=1

dài thế bạn?

:v

Tòa Versailles nhé

nhớ cho mink câu trả lời đúng ak 

và đáp án đây

Versailles

Câu 2: 

uses crt;

var i,n,t:integer;

begin

clrscr;

n:=0;

t:=0;

repeat

n:=n+1;

t:=t+n;

until t>100;

writeln(t);

readln;

end.

C2:

var i,s: integer;

begin

while s<=100 do begin

s:=s+i;

i:=i+1;

end;

write(s);

readln

end.

https://vn.answers.yahoo.com/question/index?qid=20121218203316AA1odLI

a: \(=3-2\sqrt{2}+3+2\sqrt{2}=6\)

b: \(=\sqrt{5}-\sqrt{2}-\sqrt{5}-\sqrt{2}=-2\sqrt{2}\)

\(a,=3-2\sqrt{2}+3+2\sqrt{2}=6\\ b,=5-2\sqrt{6}-5-2\sqrt{6}=-4\sqrt{6}\\ c,=2-\sqrt{3}+\sqrt{3}-1=1\\ d,=3+\sqrt{2}-\sqrt{2}+1=4\\ e,=\sqrt{\left(\sqrt{5}-\sqrt{2}\right)^2}-\sqrt{\left(\sqrt{5}+\sqrt{2}\right)^2}=\sqrt{5}-\sqrt{2}-\sqrt{5}-\sqrt{2}=-2\sqrt{2}\\ f,=\sqrt{\left(\sqrt{3}-1\right)^2}+\sqrt{\left(\sqrt{3}+1\right)^2}=\sqrt{3}-1+\sqrt{3}+1=2\sqrt{3}\\ g,=\sqrt{\left(2+2\sqrt{5}\right)^2}+\sqrt{\left(\sqrt{5}-2\right)^2}=2+2\sqrt{5}+\sqrt{5}-2=3\sqrt{5}-4\left(đáp.số.đã.cho.sai\right)\\ h,=\sqrt{\left(3-2\sqrt{2}\right)^2}+\sqrt{\left(2\sqrt{2}+1\right)^2}=3-2\sqrt{2}+2\sqrt{2}+1=4\)