Question

What is the equation, in slope-intercept form, of the line thatpasses through (0,5) and has a slope of -1?

Answer 1

Point-slope form: y - y1 = m(x - x1)
Just substitute the values, 
y - 5 = -1(x - 0)
y - 5 = -x
y = -x + 5

In short, Your Answer would be: y = -x + 5

Hope this helps!

Answer 2

y=mx+b
m=slope
b=y intercept
the y intercept is the y value when x=0
we are given (0,5) so y=5 when x=0
y intercept is 5
slope is -1

m=-1
b=5
y=mx+b
y=-1x+5
y=-x+5