Respuesta :
Answer:
30
Step-by-step explanation:
this is common sense
15x + 12y = 90
dividing throughout by 3, we would have
5x + 4y = 30
or
by equating
15x + 12y - 90=5x + 4y -30
15x -5x = 4y -12y -30 + 90
10x=60-8y
dividing throughout by 2
5x= 30-4y
5x+4y= 30