Вправа 421 алгебра Бевз гдз 7 клас
\begin{equation}\begin{aligned}
&\text { № } 421\\
&\begin{aligned}
& \text { a) } 3(4 x-1)^2-(1-4 x)=0 \\
& (4 x-1)(12 x-3+1)=0 \\
& (4 x-1)(12 x-2)=0 \\
& \begin{array}{ll}
\text { 1) } 4 x-1=0 & \text { 2) } 12 x-2=0 \\
4 x=1 & 12 x=2 \\
x_1=\frac{1}{4} & x_2=\frac{1}{6}
\end{array}
\end{aligned}\\
&\begin{aligned}
& \text { б) } x^2+6(x+2)=12 \\
& x^2+6 x+12=12 \\
& x(x+6)=0 \\
& x_1=0 ; x_2=-6
\end{aligned}\\
&\begin{aligned}
& \text { в) } 2 x^3-5\left(x^2-2\right)=10 \\
& 2 x^3-5 x^2+10=10 \\
& x^2(2 x-5)=0 \\
& x_1=0 ; x_2=2,5
\end{aligned}\\
&\begin{aligned}
& \text { г) } \frac{3}{4} \mathrm{x}^2+\frac{1}{4}\left(4-\mathrm{x}^3\right)=1 \\
& \frac{3}{4} \mathrm{x}^2+1-\frac{1}{4} \mathrm{x}^3=1 \\
& \mathrm{x}^2\left(\frac{3}{4}-\frac{1}{4} \mathrm{x}\right)=0 \\
& \mathrm{x}_1=0 \quad \begin{aligned}
\frac{3}{4}-\frac{1}{4} \mathrm{x} & =0 \\
-\frac{1}{4} \mathrm{x} & =-\frac{3}{4} \\
x & =-\frac{3}{4} \cdot\left(-\frac{4}{1}\right) \\
x_2 & =3
\end{aligned}
\end{aligned}
\end{aligned}
\end{equation}
вправи поруч
