Answer:
Part A
Plan 1
33
Plan 2
0.05x+16
0.05x+16=33
0.05x=17
17/0.05=340
341 calls would be enough.
Part B
AN easy way of doing this is by setting the equations equal to each other and then adding a variable to one side that would be the amount of calls made on plan B. Once you get rid of the initial price of 16 dollars, then you have 17 dollars to be set equal to plan B. You divide 17 by 0.05, which gives you 340, meaning that to make both plans equal to each other, you would have to make 340 calls. To make Plan 1 more economical, you would have to add 1 more call to set plan 2 0.05 cents more than Plan 2.
Explanation: