Answer:
[tex]y = - 3x + 5[/tex]
Step-by-step explanation:
to find the gradient/slope between these points:
[tex]\frac{y_{2} - y_{1}}{x_{2} - x_{1} } [/tex]
[tex] \frac{ - 1 -2}{2 - 1} = - 3[/tex]
the gradient is -3
we need to write the equation in the form y=mx+c. Choose any of the two coordinates in the question. I'll choose (1,2).
y is 2, x is 1 and m is the gradient which is -3
working out c:
[tex]y = mx + c[/tex]
[tex]2 = - 3(1) + c[/tex]
[tex]2 = - 3 + c[/tex]
add 3 on both sides
[tex]2 + 3 = c[/tex]
[tex]c = 5[/tex]
final equation:
[tex]y - = - 3x + 5[/tex]
