I don't understand part A for question 22 but to find the cost of the mugs, you have to isolate the variable. 1: 5x + 4y = 23 2: 4x + 2y = 16 step 1. 1-2= (5x - 4x) + (4y - 2y)= 23 -16 x + 2y =7 x = 7 - 2y x is equal to 7 - 2y. Next you have to find out what y is. 1: 5x + 4y =23 5(7 - 2y) + 4y = 23 35 - 10y + 4y = 23 35 - 6y = 23 6y = 35 - 23 6y/6 = 12/6 y=2 Now that you know what y is, you have to figure the rest for x. x = 7 - 2y = 7 - 2(2) <---- (y= 2) = 7-4 = 3 Now you know that x=3 and y=2. Therefore, a mug costs $3 and a glass costs $2.
This is going to be hard to draw, but you just substitute Morning mugs for x and solve, and Morning glasses for y and solve. You do the same for the night mugs for x and solve.
For A solve it in a way that if you substitute X and Y in a way it will turn out to be 23 or 16 in the <em />correct Situation.
For B substitute the X and the Y so it will match up correctly.