| x - 2 | = 3x + 7

\(\Rightarrow\orbr{\begin{cases}x-2=3x+7\\x-2=-\left(3x+7\right)\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x-2=3x+7\\x-2=-3x-7\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x-3x=7+2\\x+3x=-7+2\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}-2x=9\\4x=-5\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=\frac{-9}{2}\\x=\frac{-5}{4}\end{cases}}\)

thần đèn của năm là Ngu 123 bài toán zậy mà cũng hỏi

b² = ac

\(\Rightarrow\frac{a}{b}=\frac{b}{c}\)

\(\Rightarrow\frac{a^2}{b^2}=\frac{b^2}{c^2}=\frac{a}{b}.\frac{b}{c}=\frac{a}{c}\)

\(\Rightarrow\frac{a^2+b^2}{b^2+c^2}=\frac{a}{c}\)

a) a² = bc

\(\Rightarrow\frac{a}{c}=\frac{b}{a}\)

\(\Rightarrow\frac{a}{c}=\frac{b}{a}=\frac{a+b}{c+a}=\frac{a-b}{c-a}\)

\(\Rightarrow\frac{a+b}{a-b}=\frac{c+a}{c-a}\)

b) a² = bc

\(\Rightarrow\frac{a}{b}=\frac{c}{a}\)

\(\Rightarrow\frac{a^2}{b^2}=\frac{c^2}{a^2}=\frac{a}{b}.\frac{c}{a}=\frac{c}{b}\)

\(\Rightarrow\frac{a^2+c^2}{b^2+a^2}=\frac{c}{b}\)

(x-1/2)³=3³

=> x-1/2=3

x=3+1/2

x=7/2

(x-1/2)^3=27

(x-1/2)^3=3^3

suy ra:x-1/2=3

x=3+1/2

x=7/2

vậy x=7/2

\(\frac{x}{6}+\frac{7}{3.2^2}=\frac{17}{18}-\frac{1}{3^2}\)

\(\frac{x}{6}+\frac{7}{12}=\frac{5}{6}\)

\(\frac{x}{6}=\frac{5}{6}-\frac{7}{12}\)

\(\frac{x}{6}=\frac{1}{4}\)

\(x=\frac{1}{4}.6\)

\(x=\frac{3}{2}\)

\(\frac{a}{3}\)=\(\frac{a^2}{9}\) \(\frac{b}{7}\)= \(\frac{c}{5}\) và \(a^2\)+ \(b^2\)+ \(c^2\)= -60

\(\Rightarrow\)\(\frac{a^2}{3^2}\)= \(\frac{b^2}{7^2}\)= \(\frac{c^2}{5^2}\) và \(a^2\)+ \(b^2\)+ \(c^2\)=-60

\(\Rightarrow\)\(\frac{a^2}{9}\)= \(\frac{b^2}{49}\)= \(\frac{c^2}{25}\) và \(a^2\)+ \(b^2\)+ \(c^2\)=-60

\(\Rightarrow\)\(\frac{a^2+b^2+c^2}{9+49+25}\)= \(\frac{-60}{83}\)

Suy ra:     \(\frac{a^2}{9}\)=\(\frac{-60}{83}\)= \(\frac{-540}{83}\)

                \(\frac{b^2}{49}\)= \(\frac{-60}{83}\)= \(\frac{-2940}{83}\)

                 \(\frac{c^2}{25}\)= \(\frac{-60}{83}\)= \(\frac{-1500}{83}\)

bn ơi mik tar lời sai rùi mà hình như bn sai đề thì phải

đề như loz ai giúp đc mày

ghi lại đề đi