x + y ≤ 4
4x +8y ≤ 40
(1,2) and (2,2) are two possible solutions.
Check the graph below, please.
1) Gathering the data
CD = $4
DVD = $8
budget: $40
2) Notice the word at least. We can write two inequalities, one relating the price of each item and the budget. And the other one relating the number of CDs and DVDs to be bought.
x=CD, y= DVD
x + y ≤ 4 4 CDs and DVDs, altogether
4x +8y ≤ 40 The price of each item, as coefficient and the budget of $40
2.2) Let's plot those inequalities
Let's pick two solutions, for the common region shaded by both graphs.
Like (2, 2) and (1, 2)
3) If we plug into those inequalities we can verify them. So the answers are:
x + y ≤ 4
4x +8y ≤ 40
(1,2) and (2,2) are two possible solutions.