Remember, to write an equation, the format is:
y=mx+b
m= -2
So, the equation is:
y=-2x+b
But, what's the b value/y-intercept?
Use the given point. Plug it into the equation:
x=-1
y=5
5=-2(-1)+b
-2*-1=2
5=2+b
Subtract 2 from both sides
5-2=3
So, the y-intercept is (0,3)
The equation is:
y=-2x+3
