Question

[hgh26040912]

làm hộ đi mà hù hù cần gấp

Answer 1

[Yuri Sweet[𝕿𝖊𝖆𝖒 𝕹𝖊𝖕𝖆𝖑]]

1.a)\(\left(x+4\right)^2+8=9\)

\(\Rightarrow\left(x+4\right)^2=1\)

\(\Rightarrow\orbr{\begin{cases}x+4=1\\x+4=-1\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}x=-3\\x=-5\end{cases}}\)

Vậy ...

b)\(\left|x+6\right|=10\)

\(\Rightarrow\orbr{\begin{cases}x+6=10\\x+6=-10\end{cases}\Rightarrow}\orbr{\begin{cases}x=4\\x=-16\end{cases}}\)

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c)\(\frac{x+5}{8}+\frac{x-1}{14}+\frac{x-5}{18}+3=0\)

\(\Rightarrow\left(\frac{x+5}{8}+1\right)+\left(\frac{x-1}{14}+1\right)+\left(\frac{x-5}{18}+1\right)=0\)

\(\Rightarrow\frac{x+13}{8}+\frac{x+13}{14}+\frac{x+13}{18}=0\)

\(\Rightarrow\left(x+13\right)\left(\frac{1}{8}+\frac{1}{14}+\frac{1}{18}\right)=0\)

Dễ thấy : \(\frac{1}{8}+\frac{1}{14}+\frac{1}{18}>0\)

\(\Rightarrow x+13=0\)

\(\Rightarrow x=-13\)

Vậy ...

Answer 2

[Yuri Sweet[𝕿𝖊𝖆𝖒 𝕹𝖊𝖕𝖆𝖑]]

2.Từ \(\frac{a}{2}=\frac{b}{4}=\frac{c}{5}\),đặt \(\frac{a}{2}=\frac{b}{4}=\frac{c}{5}=k\)

\(\Rightarrow\hept{\begin{cases}a=2k\\b=4k\\c=5k\end{cases}}\Rightarrow abc=2k.4k.5k=40k^3=40\)

\(\Rightarrow k^3=1\Rightarrow k=1\)

\(\Rightarrow\hept{\begin{cases}a=2.1=2\\b=4.1=4\\c=5.1=5\end{cases}}\)

Vậy ...