Answer:
b = 3
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + b ( m is the slope and b the y- intercept )
Here m = - 2 , then
y = - 2x + b ← is the partial equation
To find b substitute (5, - 7 ) into the partial equation
- 7 = - 10 + b ⇒ b = - 7 + 10 = 3
Slope-intercept form:
y = mx + b
"m" is the slope, "b" is the y-intercept (the y value when x = 0, or (0,y))

Rise is the number of units you go up(+) or down(-)
Run is the number of units you go to the right
y = -2x
This has a y-intercept of 0, so the line intersects the y-axis/goes through the origin at (0,0)
The slope is -2 or
, so from each point, you go down 2 units, and to the right 1 unit.