Bài 2: Tập hợp các số nguyên

\(a+3b⋮13\Rightarrow\left\{{}\begin{matrix}a⋮13\\3b⋮13\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}5a⋮13\\3b⋮13\end{matrix}\right.\Rightarrow5a+3b⋮13\)

-150

-275

0

-150

-275

-0

a) -150

b) -275

c)0

\(2^{5x+5}=16^{x+3}\\ \Leftrightarrow2^{5x+5}=2^{4x+12}\\ \Leftrightarrow5x+5=4x+12\\ \Leftrightarrow x=7\)

a,Tổng là 7

b,Tổng là (-9)

c,Tổng là 0

d,Tổng là (-15)

A. Tổng là 7

B. Tổng là (-9)

C. Tổng là 0

D. Tổng là (-15)

A. Tổng là 7

B. Tổng là (-9)

C. Tổng là 0

D. Tổng là (-15)

-56

-56

-56

d) \(\left(7-2x\right)^2=49\)

\(\Rightarrow\left(7-2x\right)^2=\left(\pm7\right)^2\)

\(\Rightarrow\left[{}\begin{matrix}7-2x=7\\7-2x=-7\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}2x=7-7\\2x=7+7\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}2x=0\\2x=14\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x=7\end{matrix}\right.\)

e) \(\left(9-x\right)^3=216\)

\(\Rightarrow\left(9-x\right)^3=6^3\)

\(\Rightarrow9-x=6\)

\(\Rightarrow x=9-6\)

\(\Rightarrow x=3\)

g) \(6^{x+2}+6^x=1332\)

\(\Rightarrow6^x\cdot\left(6^2+1\right)=1332\)

\(\Rightarrow6^x\cdot37=1332\)

\(\Rightarrow6^x=1332:37\)

\(\Rightarrow6^x=36\)

\(\Rightarrow6^x=6^2\)

\(\Rightarrow x=2\)

\(d,\left(7-2x\right)^2=49\)

\(\Leftrightarrow\left[{}\begin{matrix}7-2x=7\\7-2x=-7\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}2x=0\\2x=14\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=7\end{matrix}\right.\)

\(e,\left(9-x\right)^3=216\)

\(\Leftrightarrow\left(9-x\right)^3=6^3\)

\(\Leftrightarrow9-x=6\)

\(\Leftrightarrow x=3\)

\(f,6^{x+2}+6^x=1332\)

\(\Leftrightarrow6^x\left(6^2+1\right)=1332\)

\(\Leftrightarrow6^x\cdot37=1332\)

\(\Leftrightarrow6^x=36\)

\(\Leftrightarrow6^x=6^2\)

\(\Leftrightarrow x=2\)

#Urushi

\(\left(7-2x\right)^2=49=7^2=\left(-7\right)^2\\ \Rightarrow\left[{}\begin{matrix}7-2x=7\\7-2x=-7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=0\\2x=14\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=7\end{matrix}\right.\)

---

\(\left(9-x\right)^3=216=6^3\\ \Rightarrow9-x=6\Leftrightarrow x=3\\ Vậy:x=3\)

---

\(6^{x+2}+6^x=1332\\ \Leftrightarrow6^x\left(6^2+1\right)=1332\\ \Leftrightarrow6^x.37=1332\\ \Leftrightarrow6^x=\dfrac{1332}{37}=36=6^2\\ Vậy:x=2\)

mn ơi giúp mình với pls!!!

=>x^2-2x-x+2+3 chia hết cho x-2

=>\(x-2\in\left\{1;-1;3;-3\right\}\)

=>\(x\in\left\{3;1;5;-1\right\}\)

<-5 hay>-5 ạ?

Sai

đúng

đúng