Answer:
y = 3x - 1
Step-by-step explanation:
Two lines are perpendicular if the product of theirs slopes is equal -1:
y=m₁x+b₁ ⊥ y=m₂x+b₂ ⇒ m₁×m₂ = -1
y = -1/3x + 7 ⇒ m₁=-1/3
-1/3×m₂ = -1 ⇒ m₂ = 3
The y-intercept is b=-1 so the equation in slope-intercept form:
y = 3x - 1
