I need help on this plz thx

Ametalworker has a metal alloy that is 30? % copper and another alloy that is 55? % copper. how many kilograms of each alloy should the metalworker combine to create 90 kg of a 50? % copper? alloy?

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

Which of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?