Graph the image of the figure after a dilation with a scale factor of 14 centered at (5, −5)

The "formula" to figure the new points is as follows :

New point  =  ( Vertex of triangle - Dilation Center)*Scale Factor + Dilation Center

So we have

[ ( -3 , 7) - ( 5, -5)] *14  + (5, -5)  =

[ (-8, 12) ] *14  + ( 5, -5)  =

(-112, 168) + (5, -5) =

(-107, 163)

[ ( -7 , -5) - ( 5, -5)] *14  + (5, -5)  =

[ (-12, 0) ] *14 + (5, -5) =

(-168, 0) + (5, -5) =

(-163, -5)

[ ( 9 , 3 ) - ( 5, -5)] *14  + (5, -5)  =

[ (4, 8) ] *14 + (5, -5)  =

(56, 112) + (5, - 5)  =

(61, 107 )

Here's the pre and post images :