Вправа 1094 алгебра Бевз гдз 7 клас

№ 1094 $$
\begin{aligned}
& \text { a) }\left\{\begin{array}{c}
4(x-3 z)+33 z=50 \\
5(x+2 z)-3 x=18
\end{array}\right. \\
& \left\{\begin{array}{c}
4 x-12 z+33 z=50 \\
5 x+10 z-3 x=18
\end{array}\right. \\
& \left\{\begin{array}{l}
4 x+21 z=50 \\
2 x+10 z=18
\end{array}\right. \\
& \left\{\begin{array}{l}
2 x=18-10 z \\
4 x+21 z=50
\end{array}\right. \\
& \left\{\begin{array}{c}
x=9-5 z \\
4 \cdot(9-5 z)+21 z=50
\end{array}\right.
\end{aligned}
$$
$$
\begin{aligned}
& 36-20 z+21 z=50 \\
& z=50-36 \\
& z=14 \\
& x=9-5 \cdot 14 \\
& x=9-70 \\
& x=-61
\end{aligned}
$$
Відповідь: $x=-61 ; z=14$ $$
\begin{aligned}
& \text { б) }\left\{\begin{array}{c}
4 x+7=5(x+t) \\
3(x+5 t)-6 t=15
\end{array}\right. \\
& \left\{\begin{array}{c}
4 x+7=5 x+5 t \\
3 x+15 t-6 t=15
\end{array}\right. \\
& \left\{\begin{array}{c}
x=7-5 t \\
3 x+9 t=15
\end{array}\right.
\end{aligned}
$$
$$
\begin{aligned}
& 3 \cdot(7-5 t)+9 t=15 \\
& 21-15 t+9 t=15 \\
& -6 t=15-21 \\
& -6 t=-6 \\
& t=1 \\
& x=7-5 \cdot 1 \\
& x=7-5 \\
& x=2
\end{aligned}
$$ Відповідь: $x=2 ; t=1$