Giúp mik c6 với ạ
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\(a=\lim\limits_{x\rightarrow-3}\dfrac{x+3}{\left(x+3\right)\left(x-3\right)}=\lim\limits_{x\rightarrow-3}\dfrac{1}{x-3}=-\dfrac{1}{6}\)
\(b=\lim\limits_{x\rightarrow2}\dfrac{\left(x+3\right)\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}=\lim\limits_{x\rightarrow2}\dfrac{x+3}{x+2}=\dfrac{5}{4}\)
\(c=\lim\limits_{x\rightarrow4}\dfrac{\left(x-4\right)\left(x+4\right)}{\left(x+5\right)\left(x-4\right)}=\lim\limits_{x\rightarrow4}\dfrac{x+4}{x+5}=\dfrac{8}{9}\)
\(d=\lim\limits_{x\rightarrow2}\dfrac{\left(x-2\right)\left(x+2\right)}{\left(x-1\right)\left(x-2\right)}=\lim\limits_{x\rightarrow2}\dfrac{x+2}{x-1}=4\)
\(e=\lim\limits_{x\rightarrow2}\dfrac{x+7-9}{\left(x-2\right)\left(\sqrt{x+7}+3\right)}=\lim\limits_{x\rightarrow2}\dfrac{x-2}{\left(x-2\right)\left(\sqrt{x+7}+3\right)}=\lim\limits_{x\rightarrow2}\dfrac{1}{\sqrt{x+7}+3}=\dfrac{1}{6}\)
\(f=\lim\limits_{x\rightarrow1}\dfrac{x+3-4}{\left(x-1\right)\left(\sqrt{x+3}+2\right)}=\lim\limits_{x\rightarrow1}\dfrac{x-1}{\left(x-1\right)\left(\sqrt{x+3}+2\right)}=\lim\limits_{x\rightarrow1}\dfrac{1}{\sqrt{x+3}+2}=\dfrac{1}{4}\)
\(h=\lim\limits_{x\rightarrow-3}\dfrac{x+7-4}{\left(x+3\right)\left(\sqrt{x+7}+2\right)}=\lim\limits_{x\rightarrow-3}\dfrac{x+3}{\left(x+3\right)\left(\sqrt{x+7}+2\right)}=\lim\limits_{x\rightarrow-3}\dfrac{1}{\sqrt{x+7}+2}=\dfrac{1}{4}\)
Bài 1:
a,
= limx->-3 \(\dfrac{x+3}{\left(x+3\right)\left(x-3\right)}\)
= limx->3 x-3
= -3 -3
= -6
b,
= limx->2 \(\dfrac{\left(x-2\right)\left(x+3\right)}{\left(x-2\right)\left(x+2\right)}\)
= limx->2 \(\dfrac{x+3}{x+2}\)
= \(\dfrac{5}{4}\)
c,
= limx->4 \(\dfrac{\left(x-4\right)\left(x+4\right)}{\left(x-4\right)\left(x+5\right)}\)
= limx->4 \(\dfrac{\left(x+4\right)}{\left(x+5\right)}\)
= \(\dfrac{8}{9}\)
d,
= limx->2 \(\dfrac{\left(x-2\right)\left(x+2\right)}{\left(x-2\right)\left(x-1\right)}\)
= limx->2 \(\dfrac{\left(x+2\right)}{\left(x-1\right)}\)
= 4
2:
uses crt;
var a:array[1..30]of integer;
i,dem:integer;
begin
clrscr;
for i:=1 to 30 do
begin
write('A[',i,']='); readln(a[i]);
end;
dem:=0;
for i:=1 to n do
if a[i] mod 5<>0 then inc(dem);
writeln('So phan tu khong chia het cho 5 la: ',dem);
readln;
end.
a: Xét ΔABC có
M là trung điểm của bC
I là trung điểm của AC
Do đó: MI là đường trung bình của ΔABC
Suy ra: MI=AB/2=3(cm)
\(2CH_4 \xrightarrow{làm\ lạnh\ nhanh,t^o}C_2H_2 + 3H_2\\ C_2H_2 + H_2 \xrightarrow{t^o,PbCO_3} C_2H_4\\ C_2H_4 + H_2O \xrightarrow{H^+} C_2H_5OH\\ C_2H_5OH \xrightarrow{t^o,xt} C_2H_4 + H_2O\\ C_2H_2 + H_2O \xrightarrow{xt} CH_3CHO\\ C_2H_5OH + CuO \xrightarrow{t^o} CH_3CHO + Cu + H_2O\)