we can select any two points and find slope
(x,y)=(-1,1)
(x,y)=(1,2)
now, we can use slope formula
[tex] m=\frac{y_2-y_1}{x_2-x_1} [/tex]
[tex] m=\frac{2-1}{1+1} [/tex]
[tex] m=\frac{1}{2} [/tex]
now, we can use formula
[tex] y=mx+b [/tex]
Here b is y-intercept
we can plug back m
[tex] y=\frac{1}{2}x+b [/tex]
now, we can take any one point to find b
(x,y)=(-1,1)
[tex] 1=\frac{1}{2}*-1+b [/tex]
[tex] b=\frac{3}{2} [/tex]............Answer