Math
evaluate
4r-4 when r=3
i'm not sure how to work this out, show me in steps

Perform the required operations on the following functions given: f(x)= 3-x; g(x)= -2x find g[f(x)]

Ineed asap.i cant understand this question i need someone to me right away

Ametal rod needs to be 9 feet and 5.5 inches in length. the sections of the poles being used are each 1 foot and 10.5 inches long. how many 1ft 10.5in sections would be needed to complete the 9ft 5.5in metal rod? and how many inches of material will be left?