=x + 8+ 63

=x+71

=>x-17+88

=>x+71

a² + 2a + 2 là bội của a + 2

<=> a² + 2a + 2 chia hết cho a + 2

\(\Leftrightarrow a\left(a+2\right)+2⋮a+2\)

Vì a thuộc Z => a( a + 2 ) thuộc Z 

\(\Rightarrow a\left(a+2\right)+2⋮a+2\Leftrightarrow2⋮a+2\)

\(\Leftrightarrow a+2\inƯ\left(2\right)=\left\{\pm1;\pm2\right\}\)

\(\Leftrightarrow a\in\left\{-3;-2;-4;0\right\}\)

Vậy a = -4; -3; -2; 0

\(3\left(x-5\right)-2\left(x+4\right)=-1\)

\(\Rightarrow3x-15-2x-8=-1\)

\(\Rightarrow3x-2x=-1+8+15\)

\(\Rightarrow x=22\)

\(\left|x-3\right|-5^2=\left(-5\right).4\)

\(\Rightarrow\left|x-3\right|=5\)

\(\Rightarrow\orbr{\begin{cases}x-3=5\\x-3=-5\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=8\\x=-2\end{cases}}\)

\(-14-2\left|x-5\right|=0\)

\(\Rightarrow2\left|x-5\right|=-14\)

Vì \(\left|x\right|\ge0\Rightarrow2\left|x-5\right|=-14\)(vô lí)

\(\left(3x+1\right)^2=49\)

\(\Rightarrow\left(3x+1\right)^2=\left(\pm7\right)^2\)

\(\Rightarrow\orbr{\begin{cases}3x+1=7\\3x+1=-7\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=2\\x=-\frac{8}{3}\end{cases}}\)

hùng dz

3 . (-14 )mũ 2 < (-23). (-19)

(7-|x|).(2x-4)=0 \(\Leftrightarrow\)\(\orbr{\begin{cases}7-|x|=0\\2x-4=0\end{cases}}\Rightarrow x=-7\&7\&2\)

7-IxI=0  IxI=7-0  x=0

2x-4=0  2x=0+4=4    x=4:2=2

x=0;2

= 300000

=125.-8.-25.4.1.9:3

=-1000.-100.3

=100000.3=300000

ngũ là j thế nhóc 

x² - 9 = 0

x² = 9

x = 3 ( vì 3² = 9)

x² - 16 = 0

x² = 16

x = 4 ( vì 4² = 16)