\(a,5x-5\left(-3\right)=15\)
\(\Leftrightarrow5x+15=15\)
\(\Leftrightarrow5x=0\)
\(\Leftrightarrow0\)
\(b,x=\frac{18.36.\left(-119\right)}{12.9.17}\)
\(=\frac{2.3^2.2^2.3^2.\left(-7\right).17}{2^2.3.17}\)
\(=\frac{-2^3.3^4.7.17}{2^2.3.17}\)
\(=-2.3^3.7\)
\(\left|2x\right|=\left|-5+7+8\right|\)
\(\Leftrightarrow\left|2x\right|=10\)
\(\Leftrightarrow\orbr{\begin{cases}2x=10\\-2x=10\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=5\\x=-5\end{cases}}\)
\(d,\frac{-2x}{-7.8}=\frac{14}{-56}\)
\(\Leftrightarrow\frac{x}{28}=-\frac{1}{4}\)
\(\Leftrightarrow x=-7\)
a) 5x - 5 (-3) = 15
<=> 5x + 15 = 15
<=> 5x = 15 - 15
<=> 5x = 0
<=>. x = 0
b)\(x=\frac{18\times36\times\left(-119\right)}{12\times9\times17}\)
\(\Leftrightarrow x=-42\)
d)\(\frac{-2x}{-7\times8}=\frac{14}{-56}\)
\(\Leftrightarrow-2x=14\)
\(\Leftrightarrow x=\frac{14}{-2}=-7\)
