7,5х-2,46х=78,3+124,56
5,04x = 202,86
x = 40,25
ответ: х = 40,25.
1.
\begin{gathered} < var > \\y=e-\ln x\\ y'=-\frac{1}{x}\\ < /var > \end{gathered}
<var>
y=e−lnx
y
′
=−
x
1
</var>
2.
\begin{gathered} < var > \\y=\ln(10-5x)\\ y'=\frac{1}{10-5x}\cdot-5\\ y'=\frac{-5}{10-5x}\\ y'=\frac{-5}{5(2-x)}\\ y'=\frac{1}{x-2} < /var > \end{gathered}
<var>
y=ln(10−5x)
y
′
=
10−5x
1
⋅−5
y
′
=
10−5x
−5
y
′
=
5(2−x)
−5
y
′
=
x−2
1
</var>
3.
\begin{gathered} < var > \\y=3-4\ln (1-x)\\ y'=-4\cdot\frac{1}{1-x}\cdot(-1)\\ y'=-\frac{4}{x-1} < /var > \end{gathered}
<var>
y=3−4ln(1−x)
y
′
=−4⋅
1−x
1
⋅(−1)
y
′
=−
x−1
4
</var>
4.
\begin{gathered} < var > \\y=\ln \frac{1}{x}\\ y'=\frac{1}{\frac{1}{x}}\cdot(-\frac{1}{x^2})\\ y'=-\frac{x}{x^2}\\ y'=-\frac{1}{x} < /var > \end{gathered}
<var>
y=ln
x
1
y
′
=
x
1
1
⋅(−
x
2
1
)
y
′
=−
x
2
x
y
′
=−
x
1
</var>
5.
\begin{gathered} < var > \\y=1-3^x\\ y'=-3^x \ln 3 < /var > \end{gathered}
<var>
y=1−3
x
y
′
=−3
x
ln3</var>
7.5х-2.46х=78.3+124.56
5,04х=202,86
х=202,86:5,04
х=40,25