Question

how to write slope-intercept form through (-1,3) and a slope of -1

Answer 1

The slope-intercept form:

$y=mx+b$

m - slope

b - y-intercept

We have the slope m = -1 and the point (-1, 3). Substitute:

$3=(-1)(-1)+b$

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

$2=b\to b=2$

Answer: y = -x + 2