Asequence of transformations maps ∆abc onto ∆a″b″c″. the type of transformation that maps ∆abc onto ∆a′b′c′ is
when ∆a′b′c′ is reflected across the line x = -2 to form ∆a″b″c″, vertex (note: enter your response using apostrophes instead of
of ∆a″b″c″ will have the same coordinates as b′.

Refer to the figure shown below.

The transformation that maps ΔABC onto ΔA'B'C' is a reflection across the x-axis (or across the line y = 0).

When ΔA'B'C' is reflected across the line x = -2 (shown in the figure) to form ΔA"B"C", the vertex of ΔA"B"C" will have the same coordinates as B', which is (-2,-6).