Need help with #15. please need answer and steps

1- identificar select the category that corresponds to each term. january 23 11: 59 pm unlimited attempts remaining grade settings 276-279 vocabulary list modelo fiesta quinceañera casada adolescencia viudo juventud navidad niñez vejez aniversario de bodas divorciado madurez cumpleaños soltera

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Ateacher wanted to buy a chair, a bookshelf, two tables and a desk. she spent $900 for all five items and the chair and the desk combined 70% of her total. if the bookshelf cost $50, how much did each of the tables cost?