79. Write the equation of the line that intercepts segments on the coordinate axes, the lengths of which are respectively equal to 3 and -5.
Solution. We will use the equation of a straight line in segments (7). According to the condition, \(a=3, b=-5\), therefore (Fig. 16),

$$
\frac{x}{3}+\frac{y}{-5}=1 \text { or } \frac{x}{3}-\frac{y}{5}=1 .
$$

![](https://cdn.mathpix.com/cropped/2024_05_22_1b9a1c1720bae4af5bc5g-027.jpg?height=349&width=389&top_left_y=424&top_left_x=127)

Fig. 15

![](https://cdn.mathpix.com/cropped/2024_05_22_1b9a1c1720bae4af5bc5g-027.jpg?height=335&width=398&top_left_y=438&top_left_x=658)

Fig. 16