Question

What is the equation of the blue line? (see photo)

Answer 1

y= -x-1

Explanation:

(x1,y1) = (-1,0) ; (x2,y2) = (0,-1)

y=mx+b

m=
`(y2-y1)/(x2-x1)`=
`(-1-0)/(0-(-1))`=
`(-1-0)/(0+1)`=
`(-1)/(1)`=-1

Then substitute either x1y1 or x2y2 (it's gonna give the same answer anyways) and m to find b.

y=mx+b

0=(-1)(-1)+b

0=1+b

0-1=1-1+b

b=-1

Then substitute b and m to get the equation.

y=(-1)x+(-1)

y= -x-1