. Mức cung (S) và mức cầu (D) về một loại hàng A trên thị trường được cho như sau : S = 0,3 p 0,08 ; D = 0,1 p - 0,04M 0,03q 0,01 trong đó p là giá của hàng hóa A, q là giá hàng hóa B, M là thu nhập của người tiêu dùng.
a. Có ý kiến cho rằng A là hàng hóa xa xỉ, hàng hóa A và B có thể thay thế cho nhau. Hãy nhận xét các ý kiến trên.
b. Có ý kiến cho rằng khi thu nhập tăng thì mức giá cân bằng của hàng A sẽ tăng. Hãy nhận xét ý kiến này.

Quadrilateral wxyz is on a coordinate plane. segment yz is on the line x+y=7 and segment xw is on the line x+y=3. which statement proves how segments yz and xw are related

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?

Mrs. julien’s and mrs. castillejo’s classes are selling cookie dough for a school fundraiser. customers can buy packages of macadamia nut chip cookie dough and packages of triple chocolate cookie dough. mrs. julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $221.25. mrs. castillejo’s class sold 5 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $191.25. (a) write the system of equations that model the problem. be sure to explain which equation represents which situation. (b) find the cost of each type of cookie. show your work. (c) explain which method you used to solve the system and why you chose that method.