làm hộ mình câu 8 với câu 6 với ạ làm ơn

Đáp án:

8) \(\left\{ \begin{array}{l}
y = 16\\
x = 18\\
z = 15
\end{array} \right.\)

Giải thích các bước giải:

\(\begin{array}{l}
6)\left\{ \begin{array}{l}
x = \dfrac{3}{4}y\\
z = \dfrac{5}{3}y\\
2x - 3y + z = 6
\end{array} \right.\\
 \to \left\{ \begin{array}{l}
x = \dfrac{3}{4}y\\
z = \dfrac{5}{3}y\\
2.\dfrac{3}{4}y - 3y + \dfrac{5}{3}y = 6
\end{array} \right.\\
 \to \left\{ \begin{array}{l}
x = \dfrac{3}{4}y\\
z = \dfrac{5}{3}y\\
\dfrac{1}{6}y = 6
\end{array} \right.\\
 \to \left\{ \begin{array}{l}
y = 36\\
x = 27\\
z = 60
\end{array} \right.\\
8)\left\{ \begin{array}{l}
x = \dfrac{3}{4}y:\dfrac{2}{3}\\
z = \dfrac{3}{4}y:\dfrac{4}{5}\\
x + y + z = 49
\end{array} \right.\\
 \to \left\{ \begin{array}{l}
x = \dfrac{9}{8}y\\
z = \dfrac{{15}}{{16}}y\\
x + y + z = 49
\end{array} \right.\\
 \to \left\{ \begin{array}{l}
\dfrac{9}{8}y + y + \dfrac{{15}}{{16}}y = 49\\
x = \dfrac{9}{8}y\\
z = \dfrac{{15}}{{16}}y
\end{array} \right.\\
 \to \left\{ \begin{array}{l}
\dfrac{{49}}{{16}}y = 49\\
x = \dfrac{9}{8}y\\
z = \dfrac{{15}}{{16}}y
\end{array} \right.\\
 \to \left\{ \begin{array}{l}
y = 16\\
x = 18\\
z = 15
\end{array} \right.
\end{array}\)