Question

Write the equation of a line, in slope intercept form, that has a slope of 3 and passes through the point (1, -1).

Answer 1

The slope-intercept form:

$y=mx+b$

m - slope

b - y-intercept

We have the slope $m=3\to y=3x+b$

and point (1, -1). Substitute:

$-1=3(1)+b$

$-1=3+b$      subtract 3 from both sides

$-4=b\to b=-4$

Answer: $y=3x-4$