Question

Answer 1

c/\(\dfrac{3x-7}{8}=\dfrac{5}{2}\)
\(\Rightarrow3x-7=\dfrac{5\cdot8}{2}\)
\(\Rightarrow3x-7=20\)
\(\Rightarrow3x=27\)
\(\Rightarrow x=9\)
d/\(\dfrac{x}{-2}=\dfrac{-8}{x}\)
\(\Rightarrow x^2=16\)
\(\Rightarrow\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)

Answer 2

c) \(\dfrac{3x-7}{8}=\dfrac{5}{2}\)

\(\Leftrightarrow\left(3x-7\right).2=8.5\\ \Leftrightarrow6x-14=40\\ \Leftrightarrow6x=54\\ \Leftrightarrow x=9\)

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d) \(\dfrac{x}{-2}=\dfrac{-8}{x}\)

\(\Leftrightarrow x^2=\left(-2\right).\left(-8\right)\\ \Leftrightarrow x^2=16\\ \Leftrightarrow x^2=4^2\\ \Leftrightarrow\left[{}\begin{matrix}x=-4\\x=4\end{matrix}\right.\)

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