HELLO MẤY BRO¿¿
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.


Ex2 :
1. Phong said he wanted some coffee
2. Nam and Minh said they take a taxi to there
4. My mother asked me I was doing my homework.
5. I asked him what he was name

Lời giải:
a.
$(-6)+|83|-(-75)+|-37|=-6+83+75+37=-6+195=195-6=189$
b.
$(-12)-(-26)-[(-9)-|21|)=-12+26-(-9-21)=-12+26+(9+21)$
$=-12+26+30=-12+56=56-12=44$
c.
$15-(-48)-15+(-17)-|-48|=15+48-15-17-48$
$=(15-15)+(48-48)-17=-17$
d.
$-24-(-33)+|24|-(-|78|)-|33|-78$
$=-24+33+24+78-33-78$
$=(-24+24)+(33-33)+(78-78)=0$


Câu 13.
Công suất cần cẩu A:
\(P_A=\dfrac{A_1}{t_1}=\dfrac{10m_1\cdot h_1}{t_1}=\dfrac{10\cdot1100\cdot6}{1\cdot60}=1100W\)
Công suất cần cẩu B:
\(P_B=\dfrac{A_2}{t_2}=\dfrac{10m_2\cdot h_2}{t_2}=\dfrac{10\cdot800\cdot5}{30}=1333,33W\)
\(\Rightarrow P_B>P_A\)

\(\left(2x+1\right)^2-\left(x-1\right)^2\)
\(=\left(2x+1-x+1\right)\left(2x+1+x-1\right)\)
\(=3x\left(x+2\right)\)
Your bro giải xong.

Câu 26:
\(A=\left(2\sqrt{7}-2\sqrt{3}-\sqrt{7}\right)\sqrt{7}+2\sqrt{21}\\ =\left(\sqrt{7}-2\sqrt{3}\right)\sqrt{7}+2\sqrt{21}=7-2\sqrt{21}+2\sqrt{21}=7\\ B=\sqrt{\dfrac{3}{75}}=\sqrt{\dfrac{1}{25}}=\dfrac{1}{5}\)
Câu 27:
\(a,\Leftrightarrow\sqrt{x}=4\Leftrightarrow x=16\\ b,\Leftrightarrow\sqrt{\left(x-2\right)^2}=3\Leftrightarrow\left|x-2\right|=3\\ \Leftrightarrow\left[{}\begin{matrix}x=3+2=5\\x=-3+2=-1\end{matrix}\right.\)
Câu 28:
\(a,\left\{{}\begin{matrix}x=\dfrac{6^2}{3}=12\\y=\sqrt{x\left(x+3\right)}=\sqrt{12\cdot15}=10\sqrt{3}\end{matrix}\right.\\ b,\left\{{}\begin{matrix}BC=\dfrac{AC}{\sin B}=\dfrac{5}{\sin50}\approx6,5\left(cm\right)\\AB=\sqrt{BC^2-AC^2}\approx4,2\left(cm\right)\end{matrix}\right.\)
hê lô
hello cho xin tik đi mấy bro