Will the value of the expression 20 x increase decrease or stay the same as x increases hurry! need and explain

The standard distance between studs in a house is 1.5 feet. if you have a set of blueprints for a house that mark every 1.5 feet with 2 in., by how many inches will a 13-foot wall be represented?

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)

Which representation has a constant of variation of -2.5