el costo de una camisa con 20% de descuento es de $400 ¿Cual es el precio de la camisa sin descuento?

If the scale factor between two circles is 2x/5y what is the ratio of their areas?

Can some one explain how to slove specifically, what is the value of x? 0.9(x+1.4)-2.3+0.1x=1.6 enter the answer as a decimal in the box. x= ?

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?