Giải thích các bước giải:
b1. \(\begin{array}{l}
\frac{x}{4} = \frac{y}{{ - 5}} = \frac{z}{3} = \frac{t}{7} = \frac{{x + y + z + t}}{{4 - 5 + 3 + 7}} = \frac{{ - 115}}{9}\\
\to x = \frac{{ - 115}}{9}.4 = \frac{{ - 460}}{9}\\
\to y = \frac{{ - 115}}{9}.( - 5) = \frac{{575}}{9}\\
\to z = \frac{{ - 115}}{9}.3 = \frac{{ - 115}}{3}\\
\to t = \frac{{ - 115}}{9}.7 = \frac{{ - 805}}{9}
\end{array}\)
b2. \(\begin{array}{l}
\frac{x}{5} = \frac{y}{{2,3}} = \frac{z}{{8,1}} = \frac{{x + y - z}}{{5 + 2,3 - 8,1}} = \frac{8}{{ - 0,8}} = - 10\\
\to x = - 10.5 = - 50\\
\to y = - 10.2,3 = - 23\\
\to z = - 10.8,1 = - 81
\end{array}\)
b3. \(\begin{array}{l}
\frac{x}{{2,5}} = \frac{y}{4} = \frac{z}{{1,6}} = \frac{{4x}}{{10}} = \frac{{ - 8y}}{{ - 32}} = \frac{{5z}}{8} = \frac{{4x - 8y + 5z}}{{10 - 32 + 8}} = \frac{{ - 56}}{{ - 14}} = 4\\
\to x = 4.2,5 = 10\\
\to y = 4.4 = 16\\
\to z = 4.1,6 = 6,4
\end{array}\)
