These are always a little difficult, NSS....
Note that we make a $22 profit on the Type A printer and a $19 profit on the Type B printer
And we can order no more than 120 total in one one month
Let x be the number of Type A printers and y be the number of Type B printers
So.....we have these constraints
22x+ 19y ≥ 2400 and
x + y ≤ 120
And we wish to minimize the cost function given by
237x + 122y
Here's a graph of the constraints : https://www.desmos.com/calculator/qz01ip2whh
Note that the minimum cost occurs at the corner point corner point (40,80)
And that cost is 237(40) + 122(80) = $19240
So.....we should order 40 Type A printers and 80 Type B printers
Here's the second one :
"y can exceed x by no more than 200 units"......this is a fancy way of saying that
y - x ≤ 200
and we know that
x + 2y ≤ 1600
And we wish to maximize this
14x + 22y - 900
Here's a graph of the constraints : https://www.desmos.com/calculator/dgtafe0gd7
Note that the max profit is found at the corner point (400, 600) ....this will always be true.....the max - or min - will always occur at a corner point....!!!!!!