Answer:
y' = a(x'- ((h-15)/20))² + -(k-30)
Explanation:
Vertex: (h,k)
horizontally translated 15 units left: (h-15 , k)
stretch by a factor of 20: ((h-15)/20 , k)
vertically translated down 30 units: ((h-15)/20 , k-30)
reflected in the x axis: ((h-15)/20 , -(k-30))
Vertex' (h' , k'): ((h-15)/20 , -(k-30))
Equation: y' = a(x'-h')² + k'
y' = a(x'- ((h-15)/20))² + -(k-30)