Given:
The line parallel to y = −x that passes through (7, 2.5).
To find:
The slope intercept form of the given line.
Solution:
Slope intercept form of the line is
![y=mx+b](https://img.qammunity.org/2021/formulas/mathematics/middle-school/yj5waqmoy4i54laybzhhshd88hyo5w5rj5.png)
where, m is slope and b is y-intercept.
On comparing y = −x with slope intercept form, we get
![m=-1](https://img.qammunity.org/2021/formulas/mathematics/high-school/1fx57sayebku9st01vjy1wvoslji0iuyjs.png)
So, slope of y=-x is -1.
Slope of parallel lines are same. Thus, slope of required line is -1.
Required line passes through (7,2.5) with slope -1. So, the equation of line is
![y-y_1=m(x-x_1)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/ks7lzc9jj3emt3ptrdvrvr0uzhz4c0qyo5.png)
![y-2.5=-1(x-7)](https://img.qammunity.org/2021/formulas/mathematics/high-school/y4mnutakjuuob153qnpgsdcz80pyzo1ir2.png)
![y-2.5=-x+7](https://img.qammunity.org/2021/formulas/mathematics/high-school/sdsdcrcj31v1v4k9pemgftrrtxrvezoafm.png)
Add 2.5 on both sides.
![y-2.5+2.5=-x+7+2.5](https://img.qammunity.org/2021/formulas/mathematics/high-school/ko2qk0k9l5mu4g7vvsxgijjjywphog8h6d.png)
![y=-x+9.5](https://img.qammunity.org/2021/formulas/mathematics/high-school/2wgrjbks3nnltyr2hqqpviny9lwzancldy.png)
Therefore, the equation of the line that passes through (7, 2.5) is
.