Function or not a function?

Donald has x twenty-dollar bills and 11 ten-dollar bill. how much money does donald have? write your answer as an expression.

(fog)(x) if f(x)=x^2- 4 and g(x)=x^2 + 2 x, f(g(x))= f(x^2+2x) (x^2+2x)^2-4 (x^2+2x)(x^2+2x)-4 (x^4+2x^3+5x+4x^2)-4 x^4+2x^3+4x^2+5x-4 what am i doing wrong

Which situation could best be represented by this linear equation? 24x + 38y = 520 > if x represents the number of bracelets and y represents the number of rings, there were 24 more bracelets sold than rings. the total sales were $520. if x represents the number of bracelets and y represents the number of rings, there were 38 more bracelets sold than rings. the total sales were $520. if x represents the number of bracelets sold at $24 each and y represents the number of rings sold at $38 each, the total sales were $520 if x represents the number of bracelets and y represents the number of rings, there were 520 bracelets and rings sold. bracelets were $24, and rings were $38. e