Question

The slope of the line that contains the points (1, -1) and (2, 3) is 4. What is the y-intercept?

Answer 1

Y- intercept =-5
y-y1=m(x-x1)
y-(-1)=4(x-1)
y+1=4(x-1)
y+1=4x-4
y=4x-4-1
y=4x-5
Or
y=4x+b
-1=4(1)+b
-1=4+b
-1-4=b
-5=b. Y-intercept is -5