Find XY in terms of a and b

All per-unit concepts rely on ratios,meaning,to provide a type of measurement

Sara sells beaded necklaces she makes a profit of 4 dollars pn every neclace she sells which table represents the profit sara makes

What kinds of numbers make up the set of numbers called the real numbers? give examples when you explain a number type. there are a limited set of types of numbers, but an unlimited number of examples of these numbers.