Answer:
y = -2
Step-by-step explanation:
Use the formula for slope: [tex]m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]
"m" means slope, and we know it is -1.
Decide which points will be point 1 and point 2
Point 1 (-2, y) x₁ = -2 y₁ = y
Point 2 (0, -4) x₂ = 0 y₂ - -4
Substitute the "x" and "y" values into the formula
[tex]m = \frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex]
[tex]m = \frac{-4-y}{0-(-2)}[/tex] Simplify
[tex]-1 = \frac{-4-y}{2}[/tex] Remember m = -1. Get rid of the fraction
[tex]2*-1 = 2*\frac{-4-y}{2}[/tex] Multiply both sides by 2
[tex]-2 = \frac{2(-4-y)}{2}[/tex] The "2"s cancel out on the right
[tex]-2 = -4-y[/tex] Start isolating "y"
[tex]-2 +4= -4-y + 4[/tex] Add 4 to both sides
[tex]2= -y[/tex]
[tex]2/-1= -y/-1[/tex] Divide both sides by -1 to isolate "y"
-2 = y Answer
y = -2 Variable on left side
