Respuesta :

mreijepatmat
Let x be the number of doors used in the one-story houses
And let y,be the number of doors used in the two-story houses

1) 3x +12y =117
2) 4x + 12y =124
Solve by substitution and you will find x = 7 and y =8 or
7 homes wit one story and 8 homes with 2 story
Ok the answer is 21 Xd