\(Ư\left(-3\right)=\left\{\pm1;\pm3\right\}\)

\(Ư\left(6\right)=\left\{\pm1;\pm2;\pm3;\pm6\right\}\)

\(Ư\left(11\right)=\left\{\pm1;\pm11\right\}\)

\(Ư\left(-1\right)=\left\{\pm1\right\}\)

a) \(\left(-7\right).\left(-13\right)+8.\left(-13\right)=\left(-7+8\right).\left(-13\right)=-13\)

b) \(\left(-5\right)\left[-4-\left(-14\right)\right]=\left(-5\right).\left(-4\right)-\left(-5\right).\left(-14\right)=-50\)

Vì \(\left(x-y^2+z\right)^2\ge0\)

\(\left(y-2\right)^2\ge0\)

\(\left(z-3\right)^2\ge0\)

Mà \(\left(x-y^2+z\right)^2+\left(y-2\right)^2+\left(z-3\right)^2=0\)

\(\Rightarrow\) \(\left(x-y^2+z\right)^2=0;\text{ }\left(y-2\right)^2=0;\text{ }\left(z-3\right)^2=0\)

+\(\text{ }\left(y-2\right)^2=0\)

\(\Rightarrow\text{ }y-2=0\)

\(y=0+2\)

\(y=2\)

+ \(\left(z-3\right)^2=0\)

\(\Rightarrow z-3=0\)

\(z=0+3\)

\(z=3\)

+ \(\left(x-y^2+z\right)^2=0\)

\(\Rightarrow x-y^2+z=0\)

\(x-2^2+3=0\)

\(x-4=0-3\)

\(x-4=-3\)

\(x=-3+4\)

\(x=1\)

Vậy: \(x=1;\text{ }y=2;\text{ }z=3\)

It was believed that the fire was caused by a short circuit in the lift machinery

\(\Rightarrow\) The fire was believed that it was caused by a short circuit in the lift machinery

It was believed that the fire was caused by a short circuit in the lift machinery

\(\Rightarrow\) The fire was believed that it was caused by a short circuit in the lift machinery

a) <

b) <

c) <

Hình như đề sai đó bạn.

Đáp án đúng là No, they don't hoặc Yes, they do

My name is Quynh. I'm 12 years old. I go to Hai Lang Secondary school.

There are 4 people in my family. I have one brother. Both of my parents are teachers. My brother and I is go to the same school. He's very intelligent.

My favourite sport is Badminton. I play it twice a week but in summer, I play it everyday. Summer is great because it's time to hang up my shoes and relax. There is no more school and I can go to sleep late and wake up late. Relatives visit or I can visit them. I can also do some traveling and explore new places. Relaxing in the pool on a floating lounge chair enjoying cold lemonade is the ultimate experience. I like go to the beach to sunbathe, swim in the sea, go swimming and go to water parks, is fantastic. I often draw in my free time because it help me relax, and it also improve my imagination.

Cho \(M=1+\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{2006}}\)

\(2M=2+1+\dfrac{1}{2}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{2005}}\)

\(2M-M=\left(2+1+\dfrac{1}{2}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{2005}}\right)-\left(1+\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{2006}}\right)\)

\(M=2-\dfrac{1}{2^{2006}}\)