Monday : x
tuesday : 3x
wednesday : 3x - 20 = 40
thursday: 20
3x - 20 = 40
3x = 40 + 20
3x = 60
x = 60/3
x = 20
monday : 20 minutes
tuesday : 3x....3(20) = 60 minutes
wednesday : 40 minutes
thursday: 20
for a total of : 140 minutes <===
This is the answer of the equation
Our equation would be 20+4n=A
20 represents the cost of the first sheet and then we add plus 4n which represents each additional sheets which leads out to A, our average cost per sheet.
Answer:
1 is the answer you needed