Answer:
![y = - (1)/(5) x - 1](https://img.qammunity.org/2023/formulas/mathematics/high-school/jdvkg4zmtyaapz5dslzrnykmnnwu6g9td1.png)
Explanation:
Choose any 2 points on the line indicated by dots. I'll choose (5,-2) and (10,-3)
work out the gradient between these two points.
equation:
![(change \: in \: y)/(change \: in\: x) = gradient](https://img.qammunity.org/2023/formulas/mathematics/high-school/eiv10hsoxtgdblcu9j24kgyith2on7cmo8.png)
![( - 3 - ( - 2))/(10 - 5) = - (1)/(5)](https://img.qammunity.org/2023/formulas/mathematics/high-school/gc5zfybb5a7dcf0hlirtkuktadp4ei2yre.png)
the gradient is -1/5
the equation we need to write it in is y=mx+c. use one of the two coordinates chosen. I'll use (5,-2). y is -2, m is the gradient which is -1/5 and x is 5.
working out c:
![y = mx + c](https://img.qammunity.org/2023/formulas/mathematics/high-school/pvq8ckg11f8osopew7ov658g6kwn55gt2t.png)
![- 2 = - (1)/(5) (5) + c](https://img.qammunity.org/2023/formulas/mathematics/high-school/iwlwtpiqnls8tcts0za8pt62gkq40k55is.png)
![- 2 = - 1 + c \\](https://img.qammunity.org/2023/formulas/mathematics/high-school/c47gvipve9gb8m6mcd98e22ku9z4wx6olh.png)
add one to both sides.
C is -1
we now have c and the gradient, so the equation is
![y = - (1)/(5) x - 1](https://img.qammunity.org/2023/formulas/mathematics/high-school/jdvkg4zmtyaapz5dslzrnykmnnwu6g9td1.png)