How do i solve using the most efficient method? #7 explanation would be nice : )

The figure above shows the lengths of thesides of a rectangle in cm. find the valuesof x and y and then the area of the rectangle.sides: top= 3x - yleft= 3y + 4bottom= 2x + yright= 2x - 3 use both methods, elimination and substitution, if possible.

41/17 as a decimal rounded to the nearest hundredth

Apatient is to be given 35 milligrams of demerol every 4 hours. you have demerol 50 milligrams/milliliter in stock. how many milliliters should be given per dose?